The US military has not said which of its units killed bin Laden but sources say an elite division of the Navy Seals carried out the operation.
The division is said to be the Naval Special Warfare Development Group, or DevGru for short.
It is known as Seal Team Six, which is charged with secretive counter-terrorism operations and special missions
The elite unit was formed after the bungled rescue attempt during the 1979 Iran hostage crisis.
Seal Team Six is shrouded in secrecy with only a few hundred members amongst its ranks.
The White House and the US Defense Department never comment on its activities for fear of jeopardising future missions.
President Barack Obama only confirmed that “a small team of Americans” were involved in killing bin Laden.