LONDON -- British anti-terrorist police hunted Wednesday for more suspects who are feared to be in possession of ricin, a lethal toxin that was found during the arrests of six Algerians.
Police also announced the capture of a suspect linked to the six already in custody under anti-terrorism laws. Those men were arrested Sunday in raids that turned up the traces of ricin, which can kill within a matter of days. There is no antidote.
British authorities said the seventh suspect is a 33-year-old man arrested Tuesday in North London, the scene of some of the previous arrests.
Police were looking for suspects linked to an apparent makeshift laboratory in a tiny apartment above a pharmacy in Wood Green, a low-income area in North London with a large population of Muslim immigrants.
Investigators found equipment that is believed to have been used to produce the poison in the apartment.
"We are following leads, but we are not looking for a specific number of people," a Scotland Yard official said. Police were also searching for ricin that could have been removed from the apartment by those still at large, he said.
Security was visibly stepped up at airports, ports, government buildings and other potential targets of terrorists.
Ricin probably wouldn't be an effective weapon in an attack intended to cause mass casualties, according to experts. Instead, Britons worry that it could be used in a terrorist operation reminiscent of the anthrax killings in the U.S. in 2001: random sneak attacks aimed at causing widespread panic.
Authorities want Britons to be on alert for possible symptoms of ricin poisoning, which initially resemble those of a severe flu and can quickly escalate into massive organ breakdown, according to Sue Atkinson, a public health official in London.
"But from a health point of view, it's much more likely that people are going to have colds or flu or other illnesses having to do with the winter than anything to do with this," Atkinson said.
In the past, assassins in Europe and white supremacists in the U.S. have plotted to inject victims with ricin or smear the poison on doorknobs in hopes that people would touch and eventually ingest it.
Law enforcement officials in Europe believe that the case in Wood Green could be tied to the Al Qaeda terrorist network, which has trained operatives in the use of ricin and other biological and chemical weapons. There was no official confirmation Wednesday that the seven suspects are part of the reconstituted Abu Doha network, an Al Qaeda organization in France and Britain that has been targeted in recent weeks by police trying to head off an attack.
Nonetheless, the apartment where the ricin traces turned up is about 200 yards from the onetime home of an accused member of the Abu Doha network, Mustafa Labsi, 33. He was arrested here in February 2001 and is in custody in Belmarsh, a high-security prison in southeastern London, awaiting extradition to France for allegedly plotting a bomb attack on the Group of 7 summit in Lille in 1996.
As forensic experts returned to conduct further tests at the Wood Green apartment, municipal authorities told reporters that two of the jailed suspects were 17-year-old asylum seekers whom the city had housed in the apartment at public expense.
Stobart reported from London and Rotella from Paris.