Updated

Police arrested 16 suspected Al Qaeda terrorists Friday, and U.S. officials said the men may have links to the deadly ricin poison case in Britain.

Spanish authorities said those arrested were connected to recent moves against terrorist targets in Britain and France, but did not directly tie them to the ricin arrests.

Interior Minister Angel Acebes said "the network that has been dismantled had connections to the Islamic terrorists detained recently in France and the United Kingdom."

U.S. counterterrorism officials, speaking in Washington on condition of anonymity, said those arrested in Britain may have been planing to put ricin, an easy-to-make biological weapon, in food at a British military base. The official said one of those arrested worked in the food services department of that base, which was not identified. Traces of ricin were detected at one of the suspects' apartments.

The U.S. officials said the arrest in Spain marked a significant break in efforts to avert Al Qaeda attacks in Europe.

Spanish authorities said those arrested Friday had explosives, chemicals and false passports. Authorities said the men planned to attack unspecified targets.

"Those arrested were preparing to commit attacks with explosives and chemical materials," Prime Minister Jose Maria Aznar told reporters in the northwestern city of A Coruna.

There were no immediate details on the possible targets of the alleged attacks.

Investigators are still trying to figure out the extent of the connections between those detained and their target or targets. U.S. officials would not rule out that a large, multi-country terrorist attack using chemical or biological weapons was in the works, but said it is too soon to say with any certainty.

One hundred fifty police using sniffer dogs took part in the pre-dawn raids on 12 apartments in Barcelona and other cities in the northeast Catalonia region.

Mohamed Atta, one of the Sept. 11 suicide pilots, traveled to Catalonia and is believed to have met with other Al Qaeda members there months before the attacks.

Four terrorist suspects arrested in France in December had traveled to Spain and held intensive contacts with some of those arrested on Friday, Acebes said. French police say those four were planning bomb or gas attacks in France and Russia.

British police have carried out a series of arrests this month since the deadly poison ricin was found in a London apartment on Jan. 5. British police Friday declined to comment on any links between the suspects picked up Friday and those arrested in Britain.

In Italy, news reports said police found a map detailing central London earlier this week when they arrested five Moroccans in a building containing about two pounds of explosives. Authorities were questioning the suspects and were not available to confirm the report Friday.

Acebes said the new detainees had links to Usama bin Laden, the prime suspect in the Sept. 11 attacks on New York and the Pentagon, but he did not elaborate. The men were assigned to facilitate the flow of information and create infrastructure for other Islamic terrorist groups, he said.

Acebes said those detained Friday in Spain were mostly Algerian citizens and suspected members of the Salafist Group for Call and Combat, an Algerian extremist organization. He said they maintained contact with groups in Chechnya and Algeria.

He said the network was divided into two groups, one based in Barcelona and led by an Algerian he named as Mohamad Tahraqui, and the other working from Banolas in neighboring Gerona province and directed by Bard Eddin Ferdji, also an Algerian.

Police who carried out the searches found containers with some chemical components of resins and synthetic rubber. They also confiscated timing and remote-control devices of the type used in bombs, as well as documents, including forged passports.

The detainees were to be questioned in Madrid by National Court investigative magistrate Guillermo Ruiz Polanco, who authorized the operation, Acebes said.

The arrests were made at the request of authorities in Britain and France, sources close to Ruiz Polanco said, speaking on condition of anonymity.

With Friday's arrests, Spain now has detained 35 suspected Islamic terrorists since the Sept. 11 attacks, Acebes said. Most remain in jail; but several have been released on bail.