Pakistan - A suicide bomber in an auto-rickshaw blew himself up in Pakistan on Monday, killing three people while four soldiers were killed in South Waziristan when militants struck back in their captured headquarters.

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.

In the latest bomb blast, a suicide bomber detonated his explosives when police stopped him on the outskirts of the northwestern city of Peshawar.

The bomber was in a rickshaw and detonated his explosives when the rickshaw was stopped for a check, said police official Zafar Khan.

A policeman, a passerby and the rickshaw driver were killed while five people were wounded.

Police said the bomber was apparently trying to get into the city center to stage the attack, but set off his explosives as he knew he would be caught at the checkpoint.

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 Sunday.

On Sunday evening, 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 militant attacks has unsettled trade on Pakistan's stock market and the main index ended 1.93 percent lower at 8,936.48 last Friday. 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 on Monday.

ROCKET ATTACK

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 state.

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 factions are based, from where they could strike back.

Militants hit back late on Sunday, firing rockets at a security force post in Makeen and killing four soldiers, the military said. Eight militants were killed.

According to army figures, 486 militants have been killed since the offensive began while 48 soldiers have died.

There was no independent verification of casualties as reporters and other independent observers are not allowed into the war zone except on an occasional trip with the military.

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 left alone.

Separately, two paramilitary soldiers were killed in the Bajaur region, which is also on the Afghan border to the northeast of Waziristan, when a roadside bomb blew up their vehicle, government officials said.

(Additional reporting by Zeeshan Haider; Writing by Robert Birsel; Editing by Ron Popeski)