A US drone aircraft fired missiles on Friday into Pakistan's South Waziristan region, killing 10 militants, officials said, ahead of an expected Pakistani military offensive in the area.
The United States, facing a growing Afghan insurgency, began stepping up unmanned drone attacks on militant strongholds in enclaves on the Pakistani side of the border a year ago, despite Pakistani complaints.
Three missiles were fired at militant hideouts in an area near the Afghan border controlled by Pakistani Taliban leader and al Qaeda ally Baitullah Mehsud, killing 10 militants and wounding seven, two intelligence agency officials told Reuters.
They said the missiles hit an office of Mufti Noor Wali, who was once in charge of training militants for suicide attacks, but it was not known whether he was among the dead.
Pakistani troops have stepped up pressure on Baitullah Mehsud's strongholds, carrying out air strikes by jet fighters before an expected full-scale offensive.
The drone attack also came a day after thousands of US Marines launched an offensive against the Afghan Taliban in the southern Afghanistan province of Helmand, and as British troops seized important canal crossings in support of that effort.
Helmand shares a 200-km desert border with the southwestern Pakistani province of Baluchistan.
Deadly helicopter crash
A Pakistani military helicopter has crashed in the northwest of the country, killing all 26 security personnel on board, officials said.
They say the helicopter came down because of a technical fault, about 20 km from the city of Peshawar on the mountainous border of the Orakzai and Khyber ethnic Pashtun tribal regions.
The BBC reports the MI-17 helicopter had been flying back to Peshawar from the Afghan border region when the pilot put out a mayday alert. According to officials, the helicopter then came down "in a hostile area" where it was fired upon by militants.