Attackers on Friday fired rockets at Pakistan's top military academy, damaging its outer wall in a major security breach near the home where Osama bin Laden lived for years, officials said.

No one was hurt in the pre-dawn attack and it was unclear who fired the nine rockets from behind a mosque in mountains overlooking the Kakul academy, Pakistan's equivalent of West Point 30 miles (50 kilometres) from the capital.

The garrison city of Abbottabad was considered one of the safest parts of nuclear-armed Pakistan until American special forces on May 2 found and killed the Al-Qaeda founder in a compound where he apparently lived for five years.

The bin Laden raid humiliated Pakistan's powerful military, exposing it to charges of complicity or incompetence after it emerged that the world's most wanted man had lived on the doorstep of its premier academy for years.

Three rockets on Friday damaged the outer wall of the academy, which is just 500 metres (yards) from the site of the US Navy SEALs raid that seriously damaged already turbulent relations between Pakistan and the United States.

"Nine rockets were fired. Three rockets hit the boundary wall of the military academy and damaged it. No one was hurt in the attack," Imtiaz Hussain Shah, a top local government official in Abbottabad told AFP.

"We have launched a search operation," Shah added.

Mohammad Karim Khan, Abbottabad police chief, confirmed the attack.

"Three rockets hit the boundary wall. Three others landed in an open area and three others landed in a field," he said.

Officials blamed terrorists for the attack, which came one day after Pakistan's army chief, General Ashfaq Kayani, visited Abbottabad.

Shah later confirmed to AFP no arrests had yet been made and that a rooftop room had also been damaged in the attack.

"We have a security system and checkpoints on the roads, but the place they used as a launch pad is accessible from all sides and there are mountains at the back of this place," he told private TV channel Geo.

"At this stage we cannot say who was involved, but they are terrorists and we are investigating how they managed to reach this place."

Taliban and other Islamist militants are fighting an insurgency against the army, although there has been a marked decline in violence in recent months.

Considered one of the quietest towns in the northwest, nestled in pine-dotted hills and popular with day-trippers from the capital, Abbottabad is listed on Pakistan's official tourism website as a "popular summer resort".

But although it is mainly tranquil, it is close to more troubled areas.

A judicial commission is investigating how bin Laden managed to live undetected in Pakistan for so long, and whether there was any government or military collusion.

Pakistani-US ties have since reached a new low over US air strikes that killed 24 Pakistani soldiers last November, leading Pakistan to seal its Afghan border to NATO supplies and conduct a review of its alliance with Washington.