A Taliban suicide bomber killed at least 13 people in a market next to Pakistan's military headquarters on Monday, a day after one of the deadliest attacks on security forces in recent years.

A further 18 people were wounded in the blast which tore through RA bazaar in Rawalpindi, Islamabad's twin city, only 15 metres (50 feet) from the army's General Headquarters, at around 7.45 am (0245 GMT).

It came a day after the Tehreek-e-Taliban Pakistan (TTP) killed 26 soldiers and wounded at least 25 others in a suicide bombing in the northwestern town of Bannu.

Two high-profile attacks in 24 hours mark a sharp upturn in violence from the TTP after a period of relative quiet following the death of their leader Hakimullah Mehsud in a US drone strike in November.

Haroon Joya, a senior police official at the scene of Monday's blast, told reporters six soldiers and seven civilians had been killed.

"It was a suicide attack, we are collecting evidence from the spot. We have collected some body parts suspected to be of the suicide bomber," he said.

Earlier, the top government official in Rawalpindi, Sajid Zafar Dall said 18 people were wounded in the blast.

"The attack occurred when children were going to school. Our initial assessment is that the bomber was possibly on a bicycle and he then approached the target on foot," Dall said.

Rubble and human flesh

The blast left the market place a mess of twisted shutters and rubble, with pieces of human flesh scattered on the ground, an AFP reporter said.

The TTP have been waging a bloody campaign against the Pakistani state since 2007, carrying out countless bomb and gun attacks, often on military targets.

The military headquarters came under attack in 2009, when militants laid siege to the complex for 24 hours. A total of 19 people died including eight militants.

TTP spokesman Shahidullah Shahid claimed Monday's attack as payback for a deadly military raid on a radical mosque in Islamabad in 2007.

"It was carried by one of our suicide bombers to take revenge for the Red Mosque massacre," he told AFP.

"We will continue our struggle against the secular system."

Eyewitnesses described the power of the explosion.

"I was reading a newspaper after opening my shop and all of a sudden I heard a big blast," Liaqat Ali, a grocery shop owner near the site told AFP.

"The intensity of the blast threw me off my chair. I rushed outside and saw smoke and smoke everywhere. I saw injured laying and screaming on ground."

Police and commandos cordoned off the area as ambulances took wounded to a nearby military hospital.