AFP - A suicide bomber killed three people on Monday in the second attack in the Pakistani city of Peshawar in 24 hours as militants stepped up efforts to avenge a major offensive against the Taliban.

Police said the bomber got out of a rickshaw and detonated his explosives at a police checkpoint on the outer ring road of the northwestern metropolis, which runs into the Al-Qaeda and Taliban-infested tribal badlands.

Nuclear-armed Pakistan, which has suffered a wave of Islamist bombings since July 2007, has been rocked by a spike in bloodshed killing more than 350 people since the start of October and forcing troops onto the offensive in the tribal belt.

"The driver stopped his (the bomber's) rickshaw at the checkpoint and a police constable asked him to get out but he appeared reluctant," policeman Asmatullah Khan, who watched the attack from behind sandbags, told AFP.

"The constable tried to drag him out. He blew himself up soon after stepping out of the vehicle. The rickshaw driver also died," he added.

Officials said three people were killed -- a policeman and two civilians.

The blast destroyed two vehicles, left the rickshaw a mangled wreck, damaged a police van and splattered blood on the road at the small checkpoint where police erected barricades to search cars, an AFP reporter said.

"I saw a police official arguing with a rickshaw occupant, who was a young man 20 or 22 years old sporting a small beard. The man came out and there was a big blast," said van driver Qasim Khan.

Suicide attacks and bombings frequently strike the sprawling conservative Muslim city of 2.5 million people. In the deadliest attack in Pakistan in two years, a massive car bomb killed 118 people in a Peshawar market on October 28.

Doctor Zafar Iqbal at the city's main government-run Lady Reading Hospital said four bodies, including that of the bomber, were brought to the morgue.

"We received four bodies, one police official and two civilians. The fourth body was that of the suicide attacker. It was unrecognisable," he told AFP.

The attack came 24 hours after a suicide strike in a crowded cattle market in Peshawar, where devout Muslims are already making preparations to buy meat for the Eid al-Adha festival later this month.

The death toll from that incident rose to 14 on Monday. The victims included a local mayor, the target of the bombing.

The Taliban claimed responsibility for that attack, saying it was avenging Mayor Abdul Malik's efforts to raise a militia to fight Islamist rebels after he cut formerly close links to the hardline Taliban movement in 2008.

The United States has put Pakistan on the frontline of its war against Al-Qaeda, increasingly disturbed by deteriorating security in the country where suicide attacks and bombings have killed more than 2,450 people in 28 months.

There was no claim of responsibility for Monday's bombing but Pakistan's security forces have been in the crosshairs of brazen Taliban attacks since unleashing a major ground and air offensive in South Waziristan on October 17.

Late Sunday, police shot dead a would-be suicide bomber who approached a checkpoint in the heavily guarded and leafy capital Islamabad shouting "Allah Akhbar!" officials said.

Police said the man came from South Waziristan, where the homegrown Tehreek-e-Taliban Pakistan (TTP) movement has carved out bastions and where the military has claimed a string of successes in its latest anti-Taliban campaign.

Pakistan's military and civilian government have blamed recent attacks in cities on TTP militants avenging both the military offensive and the killing of their leader Baitullah Mehsud in a US missile attack in August.

Around 30,000 troops are pressing a three-pronged offensive against TTP hideouts in South Waziristan, part of the tribal belt on the Afghan border where US officials say Al-Qaeda is plotting attacks on the West.

Backed up by fighter jets and helicopter gunships, the area is a closed military zone and details are impossible to confirm independently.

Pakistan's military Sunday said that 20 insurgents had been killed in the last 24 hours, taking the total insurgent death toll to 478 in three weeks.