A North Korean ship carrying a hidden cargo of Scud missiles and believed to be heading for Yemen was intercepted in the Arabian Sea yesterday, U.S. officials said.

The incident, occurring as tension mounted over weapons inspection in Iraq, raised the spectre of a link between North Korea, a country with an active nuclear-weapons program, and Yemen, where the al-Qaeda terror network is believed to be established.

Officials said U.S. intelligence networks had tracked the ship since it left the North Korean port of Nam Po several weeks ago. It was named the Sosan and was not flying a North Korean flag, they said.

The vessel was stopped off the Yemeni island of Socotra, 480 kilometres south of the Arabian Peninsula, by two Spanish warships patrolling as part of the U.S.-led antiterrorism coalition. The vessel was boarded after crew members refused to identify themselves, Spanish Foreign Ministry spokesman Alberto Martinez Arias said.

Although two Canadian warships are also patrolling the area, a spokesman for the Department of National Defence said no Canadians were involved.

Mr. Martinez said the North Korean captain told the Spaniards that the ship was loaded with cement, but a search turned up the 12 Scud missiles as well as missile parts.

The ship was being held in the area while the search continued and as U.S. experts, who shortly afterward boarded the vessel, made sure that any explosive materials were neutralized, U.S. officials said. It was not clear where the ship was registered, a senior administration official said.

There was no suggestion that the vessel was headed for Iraq, and the administration of U.S. President George W. Bush said it would take no immediate action.

"This is an issue of concern," White House spokesman Sean McCormack said. "We are working with other governments to figure out the next step."

But a former senior U.S.-arms control official said the incident underscored the danger posed by North Korea, which has acknowledged carrying on nuclear-weapons and missile programs in contravention of international agreements.

"The combination of nuclear weapons and ballistic missiles, and especially total disregard on exporting, is a very dangerous combination," Kenneth Adelman, who served in the administration of Ronald Reagan, told CNN.

Yemen's government has co-operated with the United States in the hunt for al-Qaeda operatives linked to the Sept. 11, 2001, attacks on New York and Washington. Its rugged, sparsely populated mountains are believed to have become a refuge for members of the group after the U.S. assault on its strongholds in Afghanistan.

North Korea has been a steady supplier of missiles to the Middle East.

In April of last year, a report by the Korea Institute for Defence Analysis said North Korea exported as many as 540 ballistic missiles, including 490 Scuds, to Middle Eastern countries between 1985 and 2000. The missiles sold for $2-million (U.S.) to $12.5-million (U.S.) each, the report said.

In March of last year, South Korea's Defence Ministry said North Korea had about 500 Scud missiles and 27 mobile launchers for the weapon. Egypt has denied accusations by U.S. officials that it is trying to procure North Korean Scuds.

The hunger-stricken Stalinist state's chief reason for selling weapons is its desperate need for hard currency, said Mari Sudo, a research associate with the Center for Non-Proliferation Studies in Monterey, Calif.

"But given the fact that they did this at a very risky moment, there might be another intention," Ms. Sudo said. "It's hard to think the only motivation would be financial."

Industry in North Korea is virtually paralyzed except for weapons production and the country has been plagued by serious food shortages.

North Koreans were reduced to eating grass and leaves when rice crops failed during the mid-1990s. Relief groups say the situation has eased, but the United Nations World Food Program recently appealed for $201-million (U.S.) in food aid for North Korea.

With reports from Reuters and Associated Press