Militants fired rockets at police chasing them after a kidnapping, killing a senior police official and five other people in Pakistan's northwest Sunday, a government official said.

Elsewhere in the region, militants kidnapped 11 police officers in a tribal area that is home to a major U.S. military supply route and where a bomber recently killed dozens at a mosque, another official said.

Parts of Pakistan's northwest — especially the lawless tribal regions bordering Afghanistan — are strongholds for Al Qaeda and Taliban fighters, and security forces stationed in the area are routinely targeted for kidnapping and killing.

Cracking down on militants along the Pakistan-Afghan border is a major focus for President Barack Obama. In unveiling a new strategy for Afghanistan, Obama warned last week that for Americans, "this border region has become the most dangerous place in the world."

The six deaths occurred in Balambat area of Lower Dir, a rough region just outside the semiautonomous tribal belt.

A group of police officials, including the district police chief Khurshid Khan, were chasing militants suspected in the kidnapping of a local resident, said Syed Mohammed Javed, a high-ranking government official in the province.

In the resulting crossfire, the heavily armed insurgents managed to hit a vehicle carrying Khan and two guards, killing all three. Also caught in the crossfire were a former local mayor and his two nephews, Javed said.

Police were unable to recover the kidnapped man, and militants managed to capture two police officers as well. The militants were believed to have suffered some casualties, though no details were available.

Dir sits next to Bajur and Swat, two regions in Pakistan where the military has battled insurgents. The army says it has defeated the militants in Bajur, while it has agreed to a cease-fire as part of a peace process in Swat. There are fears that both the army operation in Bajur and the Swat truce have led some militants to seep over to other areas, including Dir.

In Khyber tribal area, meanwhile, officials began hunting for the 11 police officers after they failed to show up for duty at their post in Sheen Qamar in the Bara sector, said Manzoor Khan, a local government official.

"We investigated and found out that Islamist militants have kidnapped them," Khan said, without elaborating. "We suspect they have been taken to (neighboring) Orakzai tribal region. We haven't received any demands so far."

Security in Khyber is of particular concern because a large number of supplies bound for U.S. and NATO troops in Afghanistan pass through the region. Militants have targeted the legendary Khyber Pass as well as transport terminals in the nearby city of Peshawar.

Early Saturday, dozens of suspected militants fired rockets at a transport terminal in Peshawar, damaging a dozen shipping containers.

That attack came less than a day after a bomber blew himself up in a packed mosque in the Jamrud area of Khyber, killing at least 48 people and wounding scores more.