Suspected Islamic militants attacked a military post, and a suicide bomber rammed his vehicle, filled with explosives, into a police patrol in separate attacks in northwestern Pakistan that killed nine people, officials said.
The suicide attacker struck a police pickup truck on a security patrol on Sunday in Shangla, a mountainous district in North West Frontier Province, a police officer said on condition of anonymity because he was not authorized to make media comments.
Four officers were killed and two were wounded, he said.
Hours earlier, in the North Waziristan tribal region, south of Shangla, militants attacked a military post with rockets and assault rifles, killing one soldier. Troops at the post returned fire, killing four attackers, an intelligence official said on condition of anonymity because of the sensitive nature of his job.
Violence blamed on Islamic militants has spiked in recent weeks in northwestern Pakistan, including in the North and South Waziristan tribal areas that border Afghanistan.
Security officials have said that Arab, Central Asian and Afghan militants -- allegedly linked with al-Qaeda and the Taliban -- operate in the region.
The increase in violence also comes amid increased US pressure on Washington-backed Pakistani President Pervez Musharraf, to do more to crack down on militants in the country's tribal zone where a recent US report indicated that al-Qaeda may be regrouping.
Musharraf, who is currently facing the toughest challenge yet to his rule, is also likely to face stiff opposition in his bid to seek another term as head of state in a vote expected later this year.
The army's top spokesman, Major General Waheed Arshad, said on Friday that some 250 militants and 60 troops have died in a month of violence, including attacks on security forces near the Afghan border.