LONDON ø The new leader of Algeria's leading Islamic insurgency group has been captured.

Western diplomatic sources said the capture of Amir Saifi marked the most significant development in more than a year in the war against Al Qaida and its aligned groups. The sources said the Algerian insurgent headed a group regarded as the main subcontractor of Al Qaida and could be linked to the train bombings in Spain in March 2004 in which about 200 people were killed.

Saifi, leader of the Salafist Group for Combat and Call, was captured in Chad, the sources said. Saifi succeeded Hassan Khatab in August 2003 in what was said to have been a coup within the Salafist organization, Middle East Newsline reported. Islamic sources said Khatab was later ordered executed by Saifi.

A statement by the German federal prosecutor's office in Karlsruhe said Saifi was arrested along with an unidentified person. Saifi, known as Abdul Razik the paratrooper, was cited as the planner of a Salafist operation in which 32 European nationals were abducted in the southern Sahara Desert in Algeria in February 2003. One of those kidnapped died and the rest were released for a ransom of about $8 million in August 2003.

The sources said Saifi, 38, could be extradited to either Algeria or Germany. The Salafist brigade, with up to 4,500 members, appears on the State Department list of terrorist groups.

Saifi was almost captured in a U.S. military-led operation in March 2004, the sources said. They said Saifi and leading Salafist insurgents were pursued through southern Algeria into Chad by U.S. special operations forces in cooperation with North African militaries. Last week, a U.S. electronic reconnaissance aircraft searched northern Mali for Saifi.

Over the last few weeks Saifi has been held by a rebel group in Chad based near the Algerian border. The sources said the group was being offered millions of dollars to hand over Saifi.

Saifi was a paratrooper in the Algerian military in the early 1990s. In 1992, he was said to have been dismissed from the army because of disciplinary issues and the following year joined the Armed Islamic Group.

In 1998, Saifi and his colleagues broke off from the Islamic group and established the Salafist Brigade. Saifi was appointed the commander of the so-called Fifth District and was said to have established a huge smuggling and hijacking network in the Sahara.

The capture of Saifi has not ended Islamic insurgency attacks in Algeria and Islamic sources said the Salafist brigade has already appointed a new commander. On Tuesday, two Algerian soldiers were reported killed and 13 others were injured in bombings in eastern Algeria.