German Interior Minister Wolfgang Schaeuble drew flak Monday for considering a security policy that would allow the indefinite detention and "targeted killing" of terror suspects.

Peter Struck, parliamentary group leader of the Social Democrats, half of Chancellor Angela Merkel's left-right ruling coalition, expressed shock at Schaeuble's remarks, which included a call to ban the use of the Internet and mobile phones by foreign suspects living in Germany.

"(Schaeuble's) new proposals on banning cellular phones could only be implemented in a police state," Struck told the daily Frankfurter Rundschau.

He said Germany must draw lessons from its Nazi past, also dismissing a call made by Merkel last week to allow the military to be deployed on German soil in the event of an imminent terrorist threat.

"This argumentation is wrong because it, among other things, does not take into account the horrible experiences in German history," he said.

Under the Basic Law adopted after the Nazi era, the military may only be deployed in the event of a disaster or to provide medical back-up during major public events.

Schaeuble, seen here as a hardliner, made the comments in Monday's issue of the news weekly Der Spiegel when asked how Germany should deal with the threat of Islamist terrorism after the recent foiled bombings in Britain.

"Let's say someone knew in which cave Osama bin Laden is sitting. Someone could then fire a guided missile to kill him," he said, referring to the Al-Qaeda chief.

"But let's be honest -- the legal issues involved are still completely unresolved, above all if Germans were to be involved.

"We must try to resolve such constitutional issues as precisely as possible and create a legal foundation to have the necessary liberties in the struggle against terrorism."

He added that Germany should consider classifying terror suspects as "enemy combattants" -- mirroring a policy used by the United States since the suicide hijackings of September 11, 2001, to justify detention without criminal charge.

"If for example potential terrorists -- so-called sleepers -- cannot be deported, what will we do then? One could consider introducing a law against conspiracies, as they have in America," he said.

"The other question is whether one could treat such sleepers as combattants and intern them."

Merkel's deputy spokesman Thomas Steg said there were no current plans to implement any of Schaeuble's proposals and did not explicitly support or dismiss them, calling them "food for thought."

"The chancellor believes that in the struggle against terrorism there can be no taboo proposals," he said.

The uproar came as a bill that would allow the federal police to secretly conduct online searches of suspects' computers for incriminating data, including e-mails, drove a wedge through the governing coalition.

The Social Democrats fiercely oppose the bill. Steg said Merkel would personally mediate in the dispute.

The failed bombings in Britain have revived a debate on fighting terror in Germany, when three of the hijackers who mounted the attacks in New York and Washington in 2001 lived as students.

Germany narrowly escaped a bloodbath last July when homemade bombs placed on two regional trains failed to detonate. Two Lebanese nationals have been charged in the case.

Despite the risk of attacks, police union chief Konrad Freiberg joined the chorus against Schaeuble's proposals, calling them "irresponsible."

"Schaeuble is preparing for the day that a terror attack is carried out (in Germany) to distract attention from his own oversights," he said.

"It is as if he wants to say, 'I told you so.'"

The head of the liberal opposition Free Democrats, Guido Westerwelle, warned against a "Guantanamo-isation" of interior policy, referring to the US-run prison camp for terror suspects in Cuba which Merkel has condemned as unlawful.

But the conservative state premier of Saarland, Peter Mueller, said Berlin must do more to confront "an acute threat from international terrorism."

"Germany is not an island of the blessed," he said.