Suicide bombers stormed a mosque frequented by army officers in Pakistan's garrison city of Rawalpindi yesterday, leaving 40 people dead in an onslaught of gunfire, grenades and explosions.

Four militants launched the attack, opening fire, tossing grenades and then detonating suicide vests in a crowd gathered for Friday prayers in the city adjoining the capital Islamabad, witnesses and officials said. Rawalpindi is home to the military's headquarters and is a frequent target of Taliban insurgents, who have staged a wave of fierce attacks in recent months to avenge military offensives against them across the northwest.

"They exploded bombs inside the mosque... They opened fire on the worshippers," army spokesman Major General Athar Abbas said.

"Thirty-six people were killed and 45 injured. Four terrorists were also killed," he said, adding that the crisis ended yesterday afternoon after security forces backed by helicopters ensured all the militants were dead.

Nine army officials including a major general, a brigadier, two lieutenant colonels and two majors were killed in the attack, the military said in a statement.

The "highly tragic incident" also left 17 children and 10 civilians dead.

Witnesses reported at least five blasts. Interior Minister Rehman Malik told reporters that the men entered the mosque disguised as worshippers. "There were four suicide bombers. Two carried out suicide bombings and two were killed in firing outside the mosque by security forces," he said.

He told reporters that the explosions caused a section of the mosque roof to collapse, and said most of the dead were children and the elderly. Police on the scene said that a number of military officials were also killed.