Chemicals on Chinese Ship Usable for Arms, U.S. Says : Diplomacy: Cargo is in Iranian waters. Beijing charges U.S. bullying in monitoring the vessel.

A Chinese ship in Iranian waters is carrying “tens of tons” of chemicals that can be used to make deadly chemical weapons, U.S. intelligence officials said Monday.

“We know these chemicals are bound for Iran’s chemical weapons plants and it is a lot of tonnage, tens of tons,” said one U.S. intelligence official, who spoke on the condition that his name not be used.

China’s assistant foreign minister denied over the weekend that the ship’s cargo violates international chemical weapons law, although he did not say what was on the vessel. Beijing also protested what it called bullying by U.S. military aircraft and vessels monitoring the ship. It charged that the U.S. action had blocked the ship from delivering its cargo.

The Clinton Administration said Monday that the U.S. Navy had not interfered with the progress of the ship, which was in Iranian waters but had not docked. A State Department spokesman said the Administration is working with China and Middle East allies to arrange for the vessel to be inspected before its cargo is unloaded.

“We have expressed our concern that the shipment itself is in clear violation of those international agreements on chemical weapons,” spokesman Mike McCurry said.

If ingredients for chemical weapons are discovered on the ship, the episode may strain the slowly improving relations between the United States and China, according to U.S. officials.

Last month, China agreed to help Iran build a nuclear power plant that both countries say will be used for peaceful purposes. But some U.S. officials said they believe Iran intends to use some of the Chinese equipment in a clandestine program to develop nuclear arms.

Western officials also said that Iran has an ambitious program under way to add to its stockpile of chemical weapons. A recent congressional report said Iran possesses as much as 100 tons of mustard gas, along with unknown amounts of other chemical weapons, and may be able to produce nerve gas.

U.S. intelligence learned earlier this summer that Iran had placed a large order with China for more ingredients that could be used in chemical weapons. According to intelligence sources, the United States began tracking and photographing the vessel, the Yinhe, when it left China’s port city of Dalian on July 15.

Lt. Cmdr. Bruce Cole of the U.S. Naval Forces Central Command in the Persian Gulf told the news agency Reuters on Monday that the Yinhe is carrying two ingredients used in chemical weapons.

“The first is thiodiglycol, which is used in blister agents, and the second is thionyl chloride,” used in blister and nerve agents, he said.

China and Iran are among the 133 nations that signed a legal agreement last January that prohibits the development, production, stockpiling or use of chemical weapons. Enforcement of the accord is difficult, however, because ingredients in chemical weapons also have agricultural uses.