Security officials voiced concern over the weekend about a growing terrorism threat after a newspaper reported that German Islamists, who had been trained in camps in Pakistan, had returned to Germany in June.

The Frankfurter Allgemeine Sonntagszeitung said the German interior ministry knew about 14 Islamists from Germany who had been in Pakistan or were still there. It added that authorities were calculating that more individuals from Germany would be trained in al Qaeda-run terrorist camps.

"A new quality in threat to Germany"

The weekly said at least seven Islamists from Germany had been arrested in Pakistan over the past months and that Islamabad was likely in the next few weeks to deport the men.

"We must assume that those who have come back from Pakistan are planning attacks," August Hanning, Germany's deputy interior minister, said in an interview with the paper. "We need to do everything possible to find out who went to Pakistan and was trained there."

He added that "this is a new, specific threat and is a cause for concern. There is a new quality in the threat to Germany."

Hanning added there were several indications that al Qaeda had Germany and German installations abroad, such as embassies, in its sight.

German Interior Minister Wolfgang Schäuble echoed the view, saying there was a threat that suicide bombers were now being sent to Europe.

"There are a lot of concrete indications right up to the past few days that show that Germany has increasingly moved into the crosshairs of international terrorism," Schäuble said in an interview with the BZ am Sonntag newspaper.

Last month Schäuble said authorities needed to increase vigilance due to the possibility that militants might carry out suicide attacks on German soil. In April the US embassy in Berlin announced it was boosting security at its facilities in Germany in response to what it described as an increased threat of terrorism.

Berlin has also said it believed there may be similar training camps in Afghanistan, where Germany has more than 3,000 troops stationed as part of a NATO peacekeeping force. The Taliban has threatened to step up attacks on German troops.

Merkel supports online searches

Schäuble recently sparked controversy over comments that Germany should clarify under what conditions the constitution permits the state to target and kill terrorists.

The tough-talking Schäuble also pressed for changes in laws to allow pre-emptive detention of suspected militants and said authorities should have the right to prevent people they deem dangerous from using the Internet and mobile phones.

The proposals have been criticized for eroding civil liberties. But on Sunday, Schäuble received backing from German Chancellor Angela Merkel for creating a legal framework to allow online searches of personal computers of suspected terrorists.

"We must look the threats in the eye and take them seriously," Merkel said in an interview with public broadcaster ARD. "The interior minister has the freedom to think what needs to be done in the face of totally new threats."

The issue has for weeks been a focus of heated debate between Schäuble and German Justice Minister Brigitte Zypries.

On Monday, members of Merkel's Christian Democratic Party (CDU) urged Zypries to expand the existing catalogue of anti-terrorism measures to include penalizing training in terrorism camps and the distribution of bomb-making manuals.