The U.S. special forces members who killed al-Qaeda leader Osama bin Laden in his Pakistan hideout on May 1 have revealed how they killed the 9/11 mastermind in a book.

The "Seal Target Geronimo" authored by former Seal team commander Chuck Pfarrer revealed a version of the killing different from the those reported in the press a day after the Seal Team 6 secretly raided bin Laden's home in Abbottabad.

Pfarrer says the Seal Team Six, whose members he did not name, were never on a mission to kill bin Laden.

"I've been a Seal for 30 years and I never heard the words 'kill mission'. It's a fantasy word. If it was a kill mission you don't need Seal Team 6; you need a box of hand grenades," Pfarrer said, according to News.com.au.

Pfarrer was told by the Seal Team 6 members that the raid codenamed Operation Neptune's Spear only took 90 to 120 seconds from the time they landed their Blackhawk helicopters on the roof.

There were reports that the raid was codenamed Geronimo and it started from the ground. The Washington Post reported on May 2 that the raid took 40 minutes.

In the book, a Seal radioed the others, "Geronimo, Geronimo, Geronimo" upon sighting bin Laden, who saw the Americans and slammed his bedroom door shut. The words meant that he saw the target of the mission.

The Seals kicked open the door of bin Laden's room and found him inside with his youngest wife Amal. Bin Laden tried to use his wife as human shield while he jumped for his AK-47 rifle in his bed.

The Seals fired the first round hitting the mattress of bin Laden's king-size bed. The second round of gunfire grazed Amal's calf and hit bin Laden in the head and chest.

There was no utterance of "For God and country" when they shot bin Laden in the head and heart contrary to reports, Pfarrer said.

The Seals also told Pfarrer that the nickname for bin Laden was Bert after the muppet character in Sesame Street, an educational TV show. The Seals squad's nickname was Jedi, after the Star Wars movie character.

Seal Target Geronimo is available on the Amazon.com for $15.50 with an audio version for $19.79.

The book Seal Target Geronimo written by former Seal team commander Chuck Pfarrer details the Seals' version of the event.