By Raymond Bonner

These are some of the weapons in the arsenal of the Tamil Tigers, the guerrillas army waging a bloody war for an independent state on the tiny island nation of Sri Lanka: surface-to-air missiles from Cambodia, assault rifles from Afghanistan, mortar shells from the former Yugoslavia and Zimbabwe, 60 tons of explosives from Ukraine.

The Tigers are considered some of the more advanced and ruthless terrorists in the worked. Their suicide bombers, wearing specially sewn body vests, are among the deadliest. The cadre, including young boys and women, are so disciplined that if they are captured, they have pledged to kill themselves by taking cyanide capsules that they wear around their necks.

The Tigers describe themselves as a liberation army and for 15 years they have been fighting the majority Sinhalese in Sri Lanka. The State Department officially labels the Tigers terrorists and their ability to carry out suicide bombings like the one on Thursday that killed 36 people in Colombo, the capital, reflects their remarkable success at acquiring explosives and weapons.

A recent visit to Sri Lanka provided graphic insight into the Tigers' military procurement, and more broadly into the world's light arms trade. It showed how easy it is to find weapons, pay for them with money moved through major banks and move them across borders. It also underlined how ill prepared governments are to deal with the traffic.

Unlike the trade in heavy weapons like tanks, artillery and combat aircraft, the movement of small arms is neither monitored nor reported by most governments. Nor are there treaties governing their proliferation and use as there are for chemical biological and nuclear weapons.

Nor in most countries is it a crime to buy weapons to fight a battle in a foreign land. And yet today's regional wars - from the Balkans to Central Africa - are waged primarily with small arms: assault rifles, mortars, grenade launchers and shoulder fired missiles.

"The Tigers are on the cutting edge of arms trafficking," said Rohan Gunaratna, a leading authority on the Tigers who is currently at the Center for Study of International Terrorism at St. Andrews University in Edinburgh. Mr. Gunaratna, who has good access to Sri Lanka's intelligence services, said the Tamil Tigers have bought arms from dealers in Hong Kong, Singapore, Lebanon and Cyprus; from corrupt military officers in Thailand and Burma, and directly from governments, including those of Ukraine, Bulgaria and North Korea.

These are the same venues where other insurgencies and terrorist groups shop. Favourite arms bazaars are the states of the former Soviet bloc, like Ukraine, Bulgaria, Slovakia and Kazakhstan, countries that are long on weapons and poorly paid officials and short on cash and law enforcement. War zones gone quiet, like the former Yugoslavia, Cambodia, Afghanistan and Mozambique are other places where arms traders look for wares.

Most of these countries do not have the intelligence expertise, training or resources to monitor the illicit trafficking nor does Sri Lanka. "We are dependent on others," said Kalynanda Godage, and retired Sri Lankan ambassador.

But the United States does not monitor the Tamil Tigers either, because they are not considered a threat to the United States or to American citizens in Sri Lanka. A senior official from another major Western country described as "negligible" the intelligence resources his country devotes to the Tigers, even though they raise large sums of money in the country.

The head of the Liberation Tigers of Tamil Eelam is Vellupillai Prabhakaran, 43 years old, a fisherman's son who has become one of the most effective guerrillas leaders of his time. The chief arms trader is Kumaran Padmanathan, a 43 year old university graduate.

"That's the man they should start the manhunt for " said Mr. Godage. "He's the man who has made it possible for Prabhakaran to pursue this war."

Plenty of Money Around the World

With several forged passports and aliases, Mr. Padmanathan travels widely but his main bases have been Singapore, Yangon and Bangkok, and more recently Johannesburg, according to Sri Lankan intelligence officials and diplomats from countries where he has surfaced.

"He can pass off as any middle class Tamil," said a Tamil militant who knows Mr. Padmanathan from university days. A picture taken a couple of years ago shows Mr. Padmanathan, who is about 5 feet 7 inches tall, with black curly hair, a thick mustache and glasses.

Mr. Padmanathan has recently had bank accounts in London, Singapore and Frankfurt, according to Sri Lanka and Western intelligence officials. Accounts belonging to other Tiger cadres have been found in Denmark , Sweden, Canada and Australia, they said.

And the accounts are bulging. By some estimates the Tigers collect $ 1 million a month, mostly from the Tamil diaspora in Canada, Britain, Switzerland and Australia. (Having been designated a terrorist organization the Tamil Tigers are not allowed to raise money openly in the United States.) The Tigers also operate gasoline stations, restaurants and small shops around the world.

The Sri Lankan Government has also repeatedly charged that Tigers' ships have hauled opium from Myanmar, but Western diplomats said there is no concrete evidence of this. More credible, Western officials say, are allegations that the Tigers have links with organized criminal groups in Russia, Lithuania and Bulgaria.

Flush with funds the Tigers have picked up weapons anywhere and everywhere. Assault rifles, grenade launchers, antitank weapons and Russian made surface-to-air missiles have for example been purchased in Cambodia. One batch of missiles was bought from corrupt Cambodian generals another from the outlawed Khmer Rouge, Sri Lankan officials said.

In the early 1990s, according to a former member of the Tamil tigers the group acquired at least two American made Stinger missiles, one of the most deadly and accurate shoulder fired missiles. They cam from a shipment of Stingers that Washington gave the Afghan mujaheddin rebels during their war against the Soviet Union in the 1980's.

The Central Intelligence Agency has tried unsuccessfully to buy back Stingers to keep them out of the hands of the Tigers and other terrorist groups. But Sri Lankan intelligence officials believe that a few years ago the Tigers bought more Stingers from the American supplied stock.

The Wayward Path of 70,000 shells

One of the tigers' most recent deals reflects the mysterious nature of the arms trade. It began when the Sri Lankan Government agreed to buy 70,000 mortar shells from Zimbabwe Defense Industries. To fill the order, the company turned to an Israeli arms company, L.B.G. Military Supplies. But the 81 millimeter mortars never reached Sri Lanka or at least not the Government.

The ship carrying them disappeared last summer, apparently highjacked by the Tigers - or so it was first believed. Indeed not long after the ship was reported missing the United States Embassy in Colombo received a fax claiming the Tigers had seized it on the high seas.

But the fax did not have the telltale signs of the Tamil Tigers communiques, which whirl over telephone lines from their offices around the world. The Americans concluded it had not come from the Tigers but they do not know who did send it.

The mystery of the missing mortars has been played out in installments in the Sunday Times of Sri Lanka in articles written by Iqbal Athas, a journalist who writes often about the war against the Tigers in a manner that angers the Government. He has been verbally and physically attacked by both Government officials and thugs.

Mr. Athas's articles have provided the American and other embassies with information about the saga, but he has been unable to get to the bottom of it.

The full truth will be known only if the head of L.B.G. Military Supplies, Ben Tsouk, is ever brought to trial said the chief executive for Zimbabwe Defence Industries, Colonel T.J. Dube. "He is the only one who knows anything about everything," Mr. Dube said in an interview.

Mr. Tsouk did not respond to several telephone calls to his office in Israel seeking comment. He has told Mr. Athas that he had no connection with the sale of the mortar shells. It was Mr. Tsouk, however, who loaded the mortars on the ship. "I have checked personally part of the containers," Mr. Tsouk said in a fax to Zimbabwe Defense Industries.

But they were not loaded in the Mozambique port of Beira as has been widely reported in Sri Lanka and Zimbabwe. They were loaded in Rijeka, Croatia, Mr. Tsouk said in his fax. The Tigers did not have to hijack the ship; they were loaded on to a ship the Tigers own, the Limassol according to Mr. Athas, an assertion confirmed by Colonel Dube.

The most deadly Tiger transaction involved the purchase of explosives from the Ukraine. First a Sri Lanka Tamil in Britain set up the Euro- Ukraine consultancy Agency with offices in Kiev and London. This company then negotiated with a state-owned Ukraine company the Rubezone chemical Factory. The Tigers front company bought 10 tons of hexagon a plastic explosive like Semtex; 50 tons of trinitrotoluol or TNT and a large quantity of electric timing caps and detonator cord. The deal included 345 tons of cement and single seat sports plane, which was disassembled before shipping.

Citibank Accounts Pay for TNT

Payments for the explosives were made from a Citibank account in Singapore held by Mr. Padmanathan, the Tamil arms trader and a Dresdner Bank account in Frankfurt, held in the name of another Tiger, according to the Sri Lankan investigation. Payments for the detonators and timing caps were from a Citibank account in Athens, which passed the money through a Citibank account in New York, according to the investigation. There is no indication that the banks acted illegally in handling these payments.

The Ukraine Council of Ministers and the Ministry of Internal Affairs approved the sale. But they did not look beyond the documents provided. If they had, they would have discovered that the end-user certificate, ostensibly signed by the Bangladesh Minister of Defence was a forgery.

A spokesman for Ukraine's President, Leonid Kuchma, said the government had conducted no background checks " because the product was not for military use."

The explosives were shipped to the Tigers abroad the Swene, another Tamil Tiger ship, this one flying the Honduran flag.

Using some of the Ukraine explosives a Tiger suicide team committed what the State Department described as the deadliest terrorist act of 1996. A truck packed with a thousand pounds of explosives was detonated in front of the central bank in Colombo blowing out buildings for several blocks and killing 90 people.

A few months later, the Tigers detonated bombs on a packed commuter train. Last October, , another truck bomb in the heart of the capital ripped through a hotel and was powerful enough to blow out the windows at the top of the 39 story World Trade Center there.

And on Thursday another 36 people died in Colombo, apparently the Tamils' latest victims.