At least 12 people were killed and dozens more were wounded when a bomb ripped through a crowded marketplace in the northwestern Pakistan city of Peshawar yesterday while another suicide bombing at a security checkpoint killed six others in northwest.

"Twelve people were killed and up to 70 injured in the bomb blast that took place in a main market in Peshawar city," local police official Shahnawaz Khan told AFP.

According to a security official, the explosion was close to a Shiite mosque located in the city's main Qisakhawani bazaar, but it was not clear if it was the target. The market was packed with shoppers preparing for the Eid celebrations.

The blast ripped through a hotel and several adjoining buildings, causing mayhem among a crowd of shoppers in the busy marketplace, police officer Naveed Khalid told AFP.

The blast occurred in an area dominated by the minority Shia Muslim community, the official said, indicating it could be linked to ongoing sectarian unrest in the region.

"The bomb was apparently planted in a car parked under a bridge adjoining the market and went off when the place was full of Shia shoppers. It also destroyed several shops," the official said.

The second suicide car bomber detonated his vehicle at a checkpoint Friday after police and local tribesmen waved for him to stop, killing six people in Pakistan's troubled northwest. Another militant attack killed two police.

Five were also wounded at the checkpoint in the Orakzai tribal region, local government official Mohammed Shahid said. He didn't know if the dead were police or civilians.

Further south, police said militants armed with guns and rockets killed two officers manning another checkpoint near the town of Bannu.

Police official Taj Din said another officer was wounded.

Pakistan's army and paramilitary forces do not have a presence in Orakzai, where security is managed by tribal police. A local official said police had cordoned off the area and deployed reinforcements.

The attack is bound to increase communal tensions in the area, which has a history of bloody clashes between Shias and Sunni radicals. Dozens have been killed on both sides in the past year.

Shias account for about 20 percent of Pakistan's 160 million-strong, Sunni-majority population.

There has been an increase in sectarian attacks in northwest Pakistan, which is already reeling from an unprecedented wave of violence linked to Taliban militants operating from bases along the border with Afghanistan.

Nearly 1,500 people have been killed since July 2007 in a wave of militant bombings across Pakistan.

Meanwhile, Pakistani troops killed at least 10 militants in the northwestern Swat valley, where the military is waging an offensive against the Taliban, officials said yesterday.

Troops killed six militants in a ski resort town in the valley and destroyed their ammunition dump and hide-outs on Thursday, a security official told AFP.

They also destroyed a car packed with explosives for a possible suicide attack, the official said.

Another four militants were killed Thursday when troops intercepted their vehicle in the valley, which has been rocked by a violent campaign to impose harsh Islamic laws, he added.