LONDON ø Scud missiles and warheads bound for Syria were on a train that exploded in North Korea, according to Asian intelligence sources and South Korean newspaper reports.

A 2002 order by Syria called for the delivery of North Korean Scud D medium-range missiles along with biological and chemical warheads which are weapons of mass destruction.

The sources said North Korea had completed work on some of the missiles before the catastrophic train explosion in North Korea. But the train that exploded did not contain biological or chemical weapons agents, they said. Instead, they said the train contained Scud D missiles, warheads and fuel propellants.

Although North Korea has maintained official silence about the April 22 rail blast in a North Korean town near the Chinese border, newspapers in South Korea continue to publish reports about the incident, Middle East Newsline reported.

On Thursday, the opposition Future Korea weekly quoted an anonymous North Korean expert who said Syria has ordered a "large number" of Scud missiles with biological and chemical warheads. The North Korean said the Scud engines were produced at the so-called "January 8 Factory" in Kaechon while the missiles were assembled in the Shin-eum-ri facility in Pyongyang.

The newspaper quoted the North Korean as saying that the BW and CW warheads were assembled at the Namheung Chemical Factory and were onboard the train when it exploded in what was described as an accident. He said the casing of the missiles were produced at Factory No. 26 in Kanggye.

"These details on North Korean WMD trafficking have been of great interest because the U.S. government is expected to take extraordinary measures against North Korea over the next few months," the newspaper said.

"There is considerable evidence that North Korea had completed BW and CW warhead components for shipment to Syria in May," an Asian intelligence source who monitors North Korea said. "The shipment was to have been the first of several batches of missile and nonconventional warhead components."

The train blast on April 22 in the Ryongchon station in North Korea's North Pyongan province killed scores of people, including at least 10 Syrian technicians, the sources said. They said the Syrians aboard the trainload of missiles and warhead components were members of the state-owned Center for Scientific Research and Studies, which helps administer Syria's nonconventional weapons program.

At the same time, a South Korean daily reported that North Korea has tested an engine for the multi-staged Taepo Dong-2 liquid-fuel, intermediate-range missile.

JoongAng reported on Thursday that the missile engine underwent a successful test at the Musudan missile factory in North Korea's North Hamgyong province and could pave the way for an imminent flight test. In December 2002, an explosion was said to have destroyed Taepo Dong missile engine production facilities.

North Korea has offered the Taepo Dong to several Middle East clients, including Iran and Syria. The South Korean Defense Ministry said that in 2002 North Korea sold $60 million worth of missiles and components to Iran, Iraq, Syria and Yemen.

"U.S. intelligence agencies think that the size of the combustion trace and the amount of liquid fuel used, suggest that the test was part of an experiment to develop the Taepo Dong-2 missile," JoongAng quoted a diplomatic source as saying.