BERLIN — German Interior Minister Hans-Peter Friedrich is backing off his earlier assertion that the Obama administration’s NSA monitoring of Internet accounts had prevented five terror attacks in Germany, raising questions about other claims concerning the value of the massive monitoring programs revealed by NSA leaker Edward Snowden.

Friedrich had made the assertion about the number of attacks that the NSA programs — which scoop up records from cellphone and Internet accounts — had helped to avert after a brief visit to the United States last week. But on Tuesday, he told a German parliamentary panel, “It is relatively difficult to count the number of terror attacks that didn’t occur.” And on Wednesday, he was publicly referring to just two foiled attacks, at least one and possibly both of which appeared to have little to do with the NSA’s surveillance programs.

The questions about the programs’ value in thwarting attacks in Germany come as some members of the U.S. Congress have told Obama officials that the programs exceeded what Congress authorized when it passed laws that the administration is arguing allowed the collection of vast amounts of information on cellphone and Internet email accounts.

In Germany, the concern is that the NSA is capturing and storing as many as 500 million electronic communications each month, but Germans are getting little if anything back for what is seen as an immoral and illegal invasion of privacy.

Friedrich spent July 11-12 in the United States for meetings with U.S. officials on the NSA programs that German Chancellor Angela Merkel had requested. The point of the meetings was to gather information that would calm a building German angst over the spy scandal.

Instead of being reassured, however, opposition politicians and commentators now are talking about the arrogance of the U.S. application of “winner’s power” (a reference to the political authority the United States had here during the Cold War, when Germany was divided between east and west, and West Germany leaned heavily on America for support), and how traditionally strong relations between the two countries have been harmed by the scandal.

“German-American relations are at risk,” said Hans-Christian Stroebele, a Green Party member of the influential German intelligence oversight committee in the country’s legislature, the Bundestag, which is dominated by Merkel’s Christian Democratic Union. “The longer it takes to uncover the facts after this long silence, the more problematic it becomes. No one even bothers to deny what’s been said. It could be that German or (European Union) courts will have to deal with this.”

Even as emotions build, NSA plans for expanding a listening station in Germany were revealed this week, raising more questions.

Stroebele spoke Thursday to McClatchy, addressing Friedrich’s official report, delivered behind closed doors to the Bundestag committee. He said Friedrich received little information from the United States in his quick trip to Washington.

“We’re lucky to have had Snowden,” Stroebele said. “Without him, this surveillance that is not permissible under international law would have continued for a long time. In Germany, there are prison terms for such spying.”

Perhaps most troubling was how quickly the government backed down on the claims that the surveillance helped foil terror plots. Gisela Piltz, a Liberal Party member of the Bundestag intelligence committee, said she could not give exact details of what took place in the secret hearing but noted: “There was a clear discrepancy between the previously reported number of foiled terror attacks and the number we talked about.”

And even those cases raised questions. One of them, commonly known as the Sauerland Cell Plot, involved an alleged conspiracy in 2007 to detonate a series of car bombs in crowded places. Piltz was involved in a Bundestag study of what took place. The goal of the would-be bombers was to surpass the death and injured toll from commuter train attacks in Madrid in 2004, which killed 191 and wounded an additional 1,800.

The conspirators, who allegedly included two Germans, had gathered nearly a ton of liquid explosives.

News reports at the time mentioned an unnamed U.S. intelligence official saying that cellphone calls by the two Germans had been intercepted. But those calls were said to have been made when the Germans were leaving a terror camp in Pakistan — an entirely different scenario from the current monitoring program, which captures data from everyday citizens by casting a worldwide net.

Piltz said even that participation by U.S. intelligence agencies remains unverified.

The other case, involving four men with al-Qaida connections arrested in Dusseldorf while allegedly preparing to make a shrapnel bomb to detonate at an undecided location, also raised questions about NSA involvement. During the trial, prosecutors said they were alerted to the cell by an informant, after which they studied emails from the four. But such targeted surveillance is not the issue in the NSA programs, one of which, PRISM, reportedly taps into the computers of users of nine Internet companies, including Facebook, Google and Yahoo.

Defending NSA practices, Friedrich noted that security is a “super fundamental right.” As such it outranks fundamental rights such as privacy. German newspapers were scathing in their assessment, calling Friedrich the “idiot in charge.”

Piltz said that while terrorism is a real threat, the U.S. monitoring programs have done little to prevent it.

“Germans are not safer because of U.S. espionage,” Piltz said. “It is true Germany has been lucky not to have suffered a terror attack, but there has to be a balance. We cannot sacrifice freedom for security, and when in doubt I would always opt for freedom.”

McClatchy special correspondent Claudia Himmelreich in Berlin contributed to this report.