A Turkish citizen about to board a plane to Iran was arrested Tuesday after authorities found instructions for an Islamic holy war, a protective suit against biological and chemical warfare and material for detonators in his luggage.

Harun Aydin, 29, was taken off the plane at Frankfurt airport, German federal police spokesman Armin Thiel said.

He is "suspected of having planned serious acts of violence as a member of a terrorist group with an Islamic fundamentalist background," the federal prosecutor's office said.

A Frankfurt court ordered him detained on suspicion of membership in a criminal organization and "giving instructions for serious crimes such as murder and manslaughter."

Prosecutors said Aydin was a leading member of a Turkish militant group whose leader has been suspected of plotting a kamikaze-style attack at a pilgrimage site for Turkey's founder.

Aydin's lawyer said his client was the victim of "a chain of unfortunate circumstances" and insisted the luggage belonged to someone else.

"He's a Muslim who fulfills his duties and his prayers, and supports his religion," Michael Murat Sertsoz told ARD television.

Prosecutors said Frankfurt airport police found a CD-ROM of a training program for Islamic holy warriors. They also found protective clothing against biological and chemical warfare along with a face mask and equipment to make a detonator.

"So far, no connection is discernible" between Aydin and a Hamburg terrorist cell that investigators believe included three of the suicide hijackers involved in the Sept. 11 attacks on New York and Washington, said Frauke Scheuten, spokeswoman for the federal prosecutor's office.

In London, anti-terrorist authorities arrested a 38-year-old man Tuesday morning, Scotland Yard said. The identity of the suspect was not disclosed but police said the suspect was not directly linked to the Sept. 11 attacks on America, or to dissident members of the Irish Republican Army.

The man was arrested under a section of the Terrorism Act that deals with individuals suspected of being involved in preparing, investigating or committing acts of terrorism.

Prosecutors in Germany said Aydin was a leading member of a Cologne-based militant group headed by Turkish-born Muhammed Metin Kaplan, known as the "caliph of Cologne."

Turkish authorities suspect Kaplan was behind an uncovered plot to crash a plane, laden with bombs, into the mausoleum of Turkey's founder, Mustafa Kemal Ataturk, during the country's 75th anniversary celebrations on Oct. 29, 1998.

Turkey has sought Kaplan's extradition unsuccessfully. He is currently serving a four-year jail term in Germany for incitement connected to the killing of a rival. Aydin was a co-defendant in Kaplan's trial, which ended last November. He was acquitted for lack of evidence.

Federal prosecutors have said supporters of Kaplan's Islamic State group had contacts with Usama bin Laden in 1996 and 1997, but they have no evidence of recent contact.