Separate attacks in northwest Pakistan involving a suicide bomber and several gunmen have killed at least five people, including three police officers. VOA's Barry Newhouse reports from Islamabad that despite the violence, government representatives say they continue to pursue talks with pro-Taliban militant groups.

Police in the northwestern town of Bannu said the suicide attack occurred when a passenger in a motorized rickshaw detonated a bomb at a security checkpoint.

Meanwhile, in the Swat valley, where security forces have battled pro-Taliban militants since late last year, officials said gunmen in Matta killed two police officers guarding a local bank.

Northwest Pakistan has been gripped by violence in the past year as security forces and militant groups battle for control of the region. But the violence largely subsided after the newly elected government began holding talks with some pro-Taliban militant groups last month.

The militants, led by Baitullah Mehsud, a tribal leader from South Waziristan accused of organizing the assassination of Benazir Bhutto, have declared a ceasefire during the talks.

Mehsud has said no peace deal is possible unless Pakistani security forces first withdraw from tribal areas along the Afghan border. Representatives for Pakistan's new coalition government have rejected that demand.

Despite reports of an impasse in the negotiations, Pakistan Army spokesman General Athar Abbas tells VOA that the talks are continuing and it would be too soon to declare the ceasefire over.

"The cease-fire as far as the other side is concerned was unilaterally declared. It would be premature to say the ceasefire has been done away with. These are two incidents and we are investigating who is behind the incidents," he said.

Abbas says militants who were behind the latest attacks may not be participating in the negotiations with the government.

The ongoing talks have drawn concern in Washington, where officials fear a peace accord will allow al Qaida and pro-Taliban groups to gather strength.

On Monday, U.S. Deputy Secretary of State John Negroponte said Washington will not be satisfied until militants can no longer use the tribal regions to plan, train for or execute attacks.