BELGRADE, Yugoslavia -- Yugoslavia has become the prime target for the world's most lucrative underworld business: the illegal international weapons trade.
Massive quantities of weapons are being smuggled into the country by organizations and dealers in countries ranging from Lebanon to the United States to South Africa.
Yesterday, Yugoslav air force jets intercepted and forced down a Uganda Airlines Boeing 707 carrying 19 tons of arms and ammunition. That action came after the Ugandan pilot requested an emergency landing for refueling at Ljubljana and informed Yugoslav authorities that he was carrying "technical equipment."
The pilot's request raised suspicions at Yugoslav air force headquarters, which promptly ordered several military jets into the air to escort the Boeing to another airfield in Zagreb, where its actual cargo was ascertained, a military spokesman said.
Yugoslav authorities also ordered a Romanian Airlines Tu-154 passenger plane to land yesterday on suspicion that it was involved in an illicit arms deal, but the plane was released after an inspection.
In the past few weeks, some operations have been exposed and shut down, but customs officials say they account for only a tiny fraction of illegal arms sales to the many warring factions in Yugoslavia's civil war.
One 35,000-ton shipment of weapons, which was seized on board a fleet of ships in the port of Bar on the coast of Montenegro, in southern Yugoslavia, included at least eight helicopters, more than 50 Soviet-made T-72 tanks, anti-aircraft missiles and guns. The weapons came from Lebanon, and no destination was listed in shipping documents.
"This is more than half of all weapons that the allies gave to Marshal Tito during World War II," said Fitzroy Maclean, who headed the British military mission to Yugoslavia during that war. "You can use them to arm an army of 130,000 men."
The shipment could be the same one Lebanon confirmed selling to unidentified Yugoslav buyers in June for $325 million.
That was only one of several large deals -- carried out through a tangled web of contacts -- the total value of which is estimated to run into billions of dollars.
"Real smugglers can identify markets when it comes to weapons. The profits are high, higher even than for drugs," a senior police official said.
Underground arms sales have expanded dramatically during the past 18 months as Croatia and Slovenia plotted secession. Before their declarations of independence in June, both republics secretly bought vast quantities of arms.
Senior Slovenian officials disclosed privately earlier this year that Slovenia had bought Soviet-made surface-to-air missiles from Hungary and high-tech anti-tank and anti-aircraft missiles from Singapore.
Croatia's appetite for weapons was far greater, since it had virtually no arms to begin with. Eighteen months ago, Croatia's security forces numbered 16,000; today, the figure is 105,000.
Most of the arms for those forces were bought abroad and smuggled into the country. And, because Serbia's population is roughly double Croatia's, the Croatians distributed arms to civilians in preparation for all-out resistance in case of war.
Yugoslavia has been involved at the other end of arms trafficking for years. Informed sources said the involvement of Yugoslav companies in arms transshipment and document laundering began during the long rule of Marshal Tito, when Yugoslavia's isolation led it to develop its own arms industry.
Yugoslavia has long been an exporter of arms to such radical Arab countries as Libya and Iraq, as well as "national liberation movements" including the Palestine Liberation Organization.
Such Yugoslav companies as INEX, Progress, Centrcoop and Astra have been known to barter arms for oil.
The port of Bar is thought to have been a key point for circumventing an arms embargo during the Iran-Iraq war.
Belgrade already has condemned Hungary for illegally shipping 30,000 Kalashnikov rifles to Croatia.
An incriminating videotape of Croatia's former defense minister making that deal with Hungarian officials was broadcast on Belgrade television this year before the army put him on trial in absentia.
In the United States, two operations to ship weapons to Croatia have been uncovered in recent weeks. One involved Israeli, South African and Croatian citizens. In the second, an American and three Croats were indicted in Miami last month after a federal undercover operation uncovered a plan to ship $12 million worth of Stinger and Red-Eye missiles, night-vision equipment, M-16 rifles and other weapons to the Croatian resistance without a license.