UK: Terror suspects, poison seized
LONDON, England -- Six terror suspects are being questioned by police after traces of one of the world's deadliest poisons, ricin, were discovered at their London addresses.
Scotland Yard said on Tuesday the six men of north African origin were arrested under the Prevention of Terrorism Act after an operation by the anti-terrorist branch in north and east London.
A spokesman said "equipment and materials" were found at an address in Wood Green in the British capital where one of the men was also arrested. The men are aged from their late teens to 30s.
A woman who was also arrested in Sunday's raid has been released.
The statement gave no indication of the relationships of the six. CNN's Nic Robertson said they were arrested after police received a tip-off.
Ricin is twice as deadly as cobra venom and experts have seriously assessed its use as a weapon of mass destruction. There is no known antidote, treatment or vaccine.
Ricin is a highly toxic poison "which if ingested or inhaled can be fatal," said the statement, but it is most deadly when injected.
It was the poison used to murder a Bulgarian exile, Georgi Markov, in a political assassination in London in 1978.
If injected, ricin causes immediate death of the muscles and lymph nodes near the site of the injection. Failure of the major organs and death usually follows.
Ricin, derived from the seeds and pods of the castor bean plant, is so powerful that a single molecule inside a cell can shut down protein synthesis, killing the cell off.
If inhaled, a small amount of ricin can cause death within 36 to 48 hours from failure of the respiratory and circulatory systems.
If ingested, it causes nausea, vomiting and internal bleeding of the stomach and intestines, followed by failure of the liver, spleen and kidneys, and death by collapse of the circulatory system.
In very small doses it causes the human digestive tract to convulse -- hence the laxative effect of castor oil.
But in larger doses, ricin causes diarrhoea so severe that victims can die of shock from massive fluid and electrolyte loss.
Officials in the British health services said doctors and hospitals across the country have been alerted to symptoms of ricin poisoning.
People have died from ricin poisoning after eating castor beans. Just one seed is thought to be enough to kill a child.
The poison was analysed at Britain's top defence laboratories at Porton Down, which confirmed it was ricin.
Scotland Yard said in a statement: "Ricin is a toxic material which if ingested or inhaled can be fatal.
"We have previously said that London and indeed the rest of the UK, continues to face a range of terrorist threats from a number of different groups... we would re-iterate our earlier appeals for the public to remain vigilant and aware and report anything suspicious to police.
"We are asking people to be vigilant about their surroundings, particularly in public places and if they see anything suspicious to (call police)."
The statement added: "Intensive police investigations are continuing and forensic analysis of the premises in Wood Green will take some time to complete.
"The Metropolitan Police is doing everything possible to combat the threat of terrorism, but it is only with the help and support of the public that we can reduce the harm which it causes."
The British government has issued a series of terror warnings in recent months, saying Britons are in "the front line" because of London's strong support for the U.S.-led war on terror.
U.S. officials said in August that the Islamic extremist group Ansar al-Islam had tested ricin along with other chemical and biological agents in northern Iraq, territory controlled by Kurds, not Iraqi President Saddam Hussein.
The group is allegedly linked to al-Qaeda.
United Nations weapons inspectors who left Iraq in 1998 listed ricin among the poisons they believed Saddam produced and later failed to account for, The Associated Press reported.
Ricin has long featured in the history of biological warfare.
The U.S. Chemical Warfare Service began studying ricin as a weapon of war during World War I.
During World War II, a ricin bomb was developed at the Porton Down biological weapons establishment in Wiltshire.
Ricin was then code-named Compound W. The weapon, dubbed the W-bomb, was tested but never used on soldiers or civilians.