Thailand said Monday that an aircraft loaded with North Korean weapons was flying to Iran when it was intercepted in December but that the ultimate destination of the arms is still not known. Thai authorities seized the Ilyushin Il-76 cargo plane and its five-man crew as it landed to refuel on a flight from Pyongyang Dec. 12. Found on board were 35 tons of weapons. A Thai government report to the UN Security Council, leaked to reporters in New York over the weekend, said the aircraft, which had violated UN sanctions against North Korea, was bound for Tehran's Mahrabad Airport. But Thai government spokesman Panitan Wattanayarkorn said Monday that “to say that the weapons are going to Iran, that might be inexact.” “The report only says where the plane was going to according to its flight plan, but it doesn't say where the weapons were going to,” he said. “It's still under investigation, and the suspects are under our legal system.” The five-man crew – four from Kazakhstan and one from Belarus – remain under detention. The crew has been charged with illegal arms possession, but the charges are expected to be stiffened once the investigation wraps up, police have said. The weapons found on board the aircraft were reportedly light battlefield arms, including grenades – hardly the ones Iran's sophisticated military would need. From the start there has been speculation that the weapons were to be shipped on to some of the radical Middle Eastern groups supported by Tehran. The UN imposed sanctions in June banning North Korea from exporting any arms after the communist regime conducted a nuclear test and test-fired missiles. Impoverished North Korea is believed to earn hundreds of millions of dollars every year by selling missiles, missile parts and other weapons to some countries. Investigations by The Associated Press in several countries showed the flight was facilitated by a web of holding companies and fake addresses from New Zealand to Barcelona designed to disguise the movement of the weapons. The plane's chief pilot maintains that the aircraft was headed for Kiev, Ukraine. “I never said or confirmed the plane was routed to Iran. I only know that the plane was going to Ukraine and the cargo was to have been unloaded there. That's the information I have,” the crew's Thai lawyer, Somsak Saithong, told The Associated Press Monday.