Pakistan Arrests CIA Informants Who Led U.S. to Usama Bin Laden

May 3: A view of Usama bin Laden's compound in Abbottabad, Pakistan. (AP)

WASHINGTON -- Pakistan's top military spy agency has taken into custody  five informants for the CIA whose work over several months helped lead to the U.S. raid that killed Usama bin Laden, sources told Fox News.

Among those detained by the Inter-Services Intelligence agency (ISI) are the owner of a safe house rented to the CIA to spy on bin Laden's compound, and a Pakistani army major who is in fact a doctor, sources said.

The New York Times first reported the arrest on its website late Tuesday, saying that the detained informants included a Pakistani army major who officials said copied the license plates of cars visiting bin Laden's compound in Abbottabad in the weeks before the raid.

The ISI has denied the five were detained.

The fate of the CIA informants who were arrested was unclear because the ISI is so sinister that suspects arrested by the agency are usually never seen again. The arrest will surely heighten tensions between the U.S. and Pakistan because American officials believe Islamabad should be focused on hunting down militants, not those who helped the U.S. find terrorists like bin Laden.

American officials told the newspaper that CIA Director Leon Panetta raised the issue when he visited Islamabad last week to meet with Pakistani military and intelligence officers.

"We have a strong relationship with our Pakistani counterparts and work through issues when they arise," CIA spokeswoman Marie Harf told Fox News."Director Panetta had productive meetings last week in Islamabad. It's a crucial partnership, and we will continue to work together in the fight against Al Qaeda and other terrorist groups who threaten our country and theirs."

U.S.-Pakistani relations have been strained over the raid by Navy SEALs on Pakistani territory, which was a blow to Pakistan's military, and other issues. Officials said the arrests of the informants was just the latest evidence of the fractured relationship between the two nations.

Senate Republican leader Mitch McConnell told Fox News that the arrests shows that the U.S.-Pakistani relations is a "mixed bag."

"You know there are parts of the Pakistani intelligence service and the government and the military that are sort of on our side and parts of it that aren't," he said. "I think all of us know there must've been a faction inside the Pakistani government that was aware of Usama bin Laden's presence for five years. So Pakistan is a very mixed bag. There are people there who are allied  with us and people there who aren't."

The Times said that at a closed briefing last week, members of the Senate Intelligence Committee asked Michael Morell, the deputy CIA director, to rate Pakistan's cooperation with the United States on counterterrorism operations, on a scale of 1 to 10.

"Three," Morell replied, according to officials familiar with the exchange, the newspaper said.

American officials speaking to the Times cautioned that Morell's comment was a snapshot of the current relationship and did not represent the Obama administration's overall assessment.

Husain Haqqani, Pakistan's ambassador to the United States, said in an interview with the Times that the CIA and the Pakistani spy agency "are working out mutually agreeable terms for their cooperation in fighting the menace of terrorism. It is not appropriate for us to get into the details at this stage."

The Associated Press contributed to this report.