ISLAMABAD - BOMBINGS in the Pakistani garrison city of Rawalpindi on Tuesday killed 24 people and injured 66, and one of them involving a bus carrying defence workers is a suspected suicide attack, officials said.

The attack targeting the bus in the city's Qasim market killed 16 people and a second blast minutes later in another bazaar left eight people dead, Interior Secretary Kamal Shah said.

The bus was believed to be carrying employees of the Pakistan Atomic Energy Commission, interior ministry spokesman Brigadier Javed Cheema said. The commission was not immediately available for comment.

The white-coloured 40-seater bus was almost completely destroyed by the blast, which could be heard across the city. Rescue workers were cutting open the wreckage to pull out injured people and dead bodies.

'There was a huge bang then I saw the bus in a mangled heap. Body parts were scattered across the road and there was blood everywhere,' witness Mohammad Tahir said.

The second bomb blast happened about 3km away in the city's R.A. bazaar, killing at least five people, Brig Cheema said.

The attack, initially thought to be a motorcycle bomb, may have targeted another vehicle carrying defence employees, security officials said. It was not clear whether the casualties were civilian or military.

'We are investigating what caused the bombings,' Brig Cheema said.

'The Qasim market blast could be a suicide attack. It looks like a man boarded the bus at the last minute and he was not a defence employee. There is a possibility that he might have blown himself up,' Mr Shah said.

'In both incidents 24 people were killed and 66 injured,' he said.

City police chief Murawat Ali Shah also confirmed the death toll.

There was no immediate claim of responsibility for either blast. -- AFP