German authorities are monitoring more than 200 suspected Islamic militants as possible terrorism risks, a top security official said Thursday.
Officials have no specific evidence of any planned attacks, Manfred Klink, in charge of anti-terrorism measures for Germany's Federal Criminal Office, told a conference.
But Germany remains a potential target for al-Qaida and other extremists, in part because its troops are in the international security force in Afghanistan, said Klink, whose agency is Germany's equivalent of the FBI.
Up to 1,000 al-Qaida operatives may have fled Afghanistan after the fall of the Taliban militia in 2001, possibly reaching as far as Germany, he said.
German authorities currently have 154 investigations of suspected Islamic terrorists under way, Klink said.
He did not identify those involved, or say whether they include any of the more than 200 extremists he said are being tracked by police and Germany's domestic security agency.
Germany has stepped up anti-terror measures since it came to light that three of the suicide pilots in the Sept. 11, 2001, attacks on the United States lived and studied undetected in Hamburg.
In February, Moroccan student Mounir el Motassadeq became the first Sept. 11 suspect to be convicted anywhere when a Hamburg court sentenced him to 15 years in prison for providing logistical support to the Hamburg cell.
Justice and interior ministers from the Group of Eight countries including Germany warned this week that al-Qaida terror remains a serious threat, with sleeper cells and agents "ready to act" and bases apparently relocated outside Afghanistan.