Washington, May 3 (IANS) As many as 79 crack US commandos in four helicopters flew into Pakistan's Abbottabad city on a moonless night to take out Al Qaeda leader Osama bin Laden - and a single shot to the world's most wanted man's head completed their mission.

New York Times quoted officials as saying that the American commandos in four choppers arrived at the $1 million mansion where Osama was hiding.

The US Navy SEAL commandos took out Osama who had put up resistance. They then scrambled to wrap up the operation by flying out.

Then an unexpected development took place. One of their helicopters stalled and would not take off.

The quick-thinking commandos decided that they would blow up the helicopter, rather than allow it fall into the wrong hands. They did just that.

By the time the 40-minute operation was drawing to a close, the Pakistani military was scrambling forces as they deemed it an incursion into their territory.

"They had no idea about who might have been on there," an official was quoted as saying.

"Thankfully, there was no engagement with Pakistani forces."

The remaining choppers, with all the commandos on board, took off at 1.10 a.m.

They left women and children behind and carried away a number of documents and computer hard drives from the mansion.