At least 25 people have been killed in a US drone strike in the troubled Pakistani tribal region of North Waziristan, officials told the BBC.
Missiles were fired on a large compound in the town of Spinwam, but five women and four children in a nearby house were also killed.
The area is a haven for al-Qaeda and Taliban militants.
Meanwhile, at least 13 soldiers died when hundreds of insurgents attacked a checkpoint near the Afghan border.
Pakistani security officials told the BBC that Afghan militants had crossed the border and stormed the army post in the Lower Dir area.
Security forces temporarily abandoned the post but now, residents say, they are back in control and have placed the entire area under curfew.
Pakistani officials say four missiles were fired on a large compound occupied by supporters of local militant commander Hafiz Gul Bahadur, in Spinwam, 40km (25 miles) north-east of the tribal region’s main town of Miranshah.
Several people were also wounded in Friday’s attack, a local intelligence official was quoted as telling AFP news agency.
The US does not routinely confirm it conducts drone operations in Pakistan.
But analysts say only American forces have the capacity to deploy such aircraft. US drone attacks have escalated in the region since President Barack Obama took office. More than 100 raids were reported last year.
Many militants, some of them senior, have been killed in the raids, but hundreds of civilians have also died.
Drone strikes are are hugely unpopular with the Pakistani public. Correspondents say they have the tacit approval of the authorities, although Pakistani leaders deny secretly supporting them.
The BBC’s Ilyas Khan in Islamabad says there have been few drone attacks in Spinwam, making it a comparatively safe place for militants who have been chased out of other militant strongholds in North Waziristan.
A drone strike in North Waziristan on 17 March killed some 40 people, most of them believed to be civilians attending a tribal meeting.
In a rare public condemnation, Gen Kayani called that raid “intolerable and unjustified”.
Friday’s strike comes a day after Pakistani army chief, Gen Ashfaq Pervez Kayani, told the US military’s top officer, Adm Mike Mullen, that drone strikes complicated Pakistan’s “national” war against the militants.
It also comes amid a deepening rift between the US and Pakistan. On Wednesday Adm Mullen accused Pakistan’s spy agency of having links with militants targeting troops in Afghanistan.
Anti-American feeling has been on the rise in Pakistan, stoked by the row over CIA contractor Raymond Davis, arrested and later released after shooting dead two Pakistani men in Lahore in January.
Recent reports in the US from unnamed Pakistani officials, suggest Pakistan demanded certain restrictions to the CIA’s activities in Pakistan, including their drone programme.