PESHAWAR, Pakistan (Reuters) -- A suicide bomber in an auto-rickshaw has blown himself up in Pakistan, killing three people after police stopped him at a checkpoint on the outskirts of the city of Peshawar, police said.
Islamist militants have unleashed a campaign of attacks in Pakistan in recent weeks in retaliation for a major offensive by security forces on their main bastion of South Waziristan on the Afghan border.
"It was a suicide attack. The bomber was in a rickshaw and detonated his explosives when the rickshaw was stopped for a check," said police official Zafar Khan.
"One of our constables, a passerby, and the rickshaw driver were killed," he said. Five people were wounded.
It was the second attack in the Peshawar region in 24 hours.
A suicide bomber killed an anti-Taliban village mayor and 11 other people in an attack near the city on November 8.
On the evening of Novembe 8, police in the capital, Islamabad, shot dead a suicide bomber before he could set off his explosives as he ran toward a police checkpost.
The campaign of militant attacks has unsettled trade on Pakistan's stock market and the main index ended 1.93 percent lower at 8,936.48 on November 6. Despite the security worries, the index has gained 52 percent this year after losing 58.33 percent last year.
The market was closed for a public holiday today.
Authorities say the bomb attacks only stiffen their resolve to defeat the Pakistani Taliban in South Waziristan.
The region's rugged landscape of barren mountains and hidden ravines has become a global center of Islamist militancy and the offensive is closely watched by the United States and other powers embroiled in neighboring Afghanistan.
The army went on the offensive in the ethnic Pashtun region on October 17 aiming to root out the militants attacking the Pakistani state.
Militant factions operating in other parts of the lawless border belt, which focus on attacking Western forces in neighboring Afghanistan, are for the time being at least being left alone.
Soldiers have been advancing into the Pakistani Taliban heartland from three directions and have entered the Taliban headquarters in the town of Makeen.
Analysts say many militants appeared to have melted away, perhaps into neighboring North Waziristan where allied militant factions are based, from where they could strike back.
According to army figures, 478 militants have been killed since the offensive began while 44 soldiers have died.
There was no independent verification of casualties as reporters and other independent observers are not allowed into the war zone.