Poison seized, 6 held in London

? Police said Tuesday that they found traces of ricin — a deadly poison twice as potent as cobra venom — in a north London apartment and arrested six men of North African origin in connection with the virulent toxin that has been linked to al-Qaida terrorists and Iraq.

London police said material seized Sunday at a flat in the Wood Green neighborhood had tested positive Tuesday for traces of the toxin, tiny amounts of which can kill an adult. There is no antidote.

Prime Minister Tony Blair, speaking to a meeting of British ambassadors, said the find highlights the threat posed by weapons of mass destruction.

“As the arrests … show, this danger is present and real, and with us now, and its potential is huge,” he said.

Ricin (pronounced RICE-in) is derived from the castor bean plant, which is grown around the world. The poison is relatively easy to produce, and Andy Oppenheimer, a chemical and biological weapons expert at Jane’s Terrorism and Security Monitor, said its presence in London did not necessarily indicate a connection to any outside group or country.

In Washington, U.S. officials said no al-Qaida links had yet been established to the London arrests, but that it was a matter being investigated.

Anti-terrorist police said they arrested the six men of north African origin under the Terrorism Act during raids in east and north London and seized “a quantity of material and items of equipment” at the Wood Green apartment.

Police did not identify the men and refused to specify what country or countries they were from, saying only that they were in their late teens, 20s and 30s. They were not immediately charged with a crime.

A woman arrested in the raids was released.

The Department of Health said doctors around Britain had been informed of the find and warned to look for symptoms of ricin exposure, including fever, stomach pains, diarrhea and vomiting.

Ricin causes diarrhea so severe that victims can die of shock from massive fluid and electrolyte loss.

United Nations weapons inspectors who left Iraq in 1998 listed ricin among the poisons they believed Saddam produced. U.S. troops also found traces of the substance at suspected al-Qaida biological weapons sites in Afghanistan.