British police have arrested six more people in connection with the discovery of the highly toxic poison ricin in London, news reports said Monday.

Sky News and the British Broadcasting Corp. said five men and a woman were arrested Sunday in Bournemouth on England's south coast.

London's Metropolitan Police said only that five men and a woman had been arrested in Bournemouth in connection with "an ongoing investigation."

A spokesman told The Associated Press that local police and specialist officers from London were searching premises in the Bournemouth area. The six people arrested were in custody in Bournemouth, he said on condition of anonymity.

Last week, seven men were arrested in London after an anti-terrorist raid uncovered traces of the poison ricin in an apartment in north London's Wood Green district. Four, described as North African in origin, appeared in court Monday charged with chemical weapons and terrorism offenses.

Mouloud Feddag, 18; Samir Feddag, 26; Mustapha Taleb, 33; and a 17-year-old youth were charged with possession of articles for "the commission, preparation or instigation of an act of terrorism" and with "being concerned in the development or production of chemical weapons."

The teenager cannot be named under a judge's order.

Taleb also faces a separate charge of possessing articles for the commission, preparation or instigation of terrorism.

Ricin can kill within days. There is no antidote or treatment. It is derived from the castor bean plant, which is grown around the world.

The four sat somberly during the 30-minute hearing and spoke only to confirm their names and addresses. Mouloud Feddag's address was given as High Road, Wood Green -- where the ricin was found last week. Samir Feddag, 26, gave an address in Algiers, Algeria.

Authorities have refused to say which countries the other three are from.

The men did not apply for bail and were ordered detained until their next court appearance on Friday at London's Old Bailey criminal court.

A fifth suspect, Nasreddine Fekhadji, was charged with forgery and counterfeiting offenses.

A sixth man arrested for alleged possession of drugs and immigration offenses was expected to be released on bail, police said. A seventh man was released to the custody of immigration officials.

Ricin has been linked in the past to Usama bin Laden's Al Qaeda network in Saddam Hussein's regime in Iraq.

The U.S. Chemical Warfare Service began studying ricin as a weapon during World War I. During World War II, Britain developed, but never used, a ricin bomb.