ISLAMABAD (Reuters) - One of Osama bin Laden's wives told Pakistani interrogators that the al Qaeda leader and his family had been living for five years in the compound where he was killed by U.S. forces this week, a security official said on Friday.

The official, who identified the woman as Amal Ahmed Abdulfattah, the youngest of bin Laden's three wives, told Reuters she was wounded in the U.S. raid on Monday.

The security official said Abdulfattah told investigators: "We have been living there for the past five years."

Both Pakistan's army and its powerful spy agency, Inter-Services Intelligence (ISI), have been facing mounting pressure to explain how it was possible for bin Laden to live deep inside Pakistan undetected for years.

Pakistani security forces took between 15 and 16 people into custody from the compound after U.S. forces removed bin Laden's body, said the security official. Those detained included bin Laden's three wives and several children.

Separately, a senior Pakistani intelligence official briefing Pakistani journalists on Thursday evening said that bin Laden and his deputy, Ayman al-Zawahiri, fell out six years ago over the distribution of money. He gave no other details.

U.S. special forces used helicopters to attack the compound in Abbottabad, 50 km (30 miles) north of the capital, Islamabad.

Pakistani security officials say neither bin Laden nor his comrades offered any resistance during the raid.

"From the clues, evidence what we have got is they stormed in with firing shots and knocked them down," a security official said.

Another security official on Thursday said their killing was "cold-blooded."

The raid on the compound, around 4 kilometres (2.5 miles) from Pakistan's main military academy, has further strained relations between the two uneasy allies.

Pakistan's military top brass have expressed anger that the United States did not inform them of the attack beforehand.

In his first comment on the raid, Pakistan army chief General Ashfaq Kayani on Thursday threatened a review of military and intelligence cooperation should the United States repeat similar unilateral action.

He also told senior military commanders that it had been decided to reduce the strength of U.S. military personnel in Pakistan to the "minimum essential."

The army has admitted intelligence failures over the presence of bin Laden in the country and ordered an inquiry into these "shortcomings."

"We didn't know Osama bin Laden was hiding in this house until we took these people into custody and they confirmed that he (bin Laden) has been killed," another security official said.

The military, which has long been seen as the most effective institution of the unstable nation, has also been facing growing criticism at home over the perceived violation of country's sovereignty by the U.S. forces.

(Additional reporting by Kamran Haider; Editing by Michael Georgy and Alex Richardson)