Nearly 60 people have been killed in a series of attacks by US drones in the past 24 hours in Pakistan's Khyber tribal district, officials say.
At least 50 died in three unmanned air strikes in the Tirah Valley, a day after seven others were killed nearby.
Security officials say all the dead in the attacks are militants - a claim that cannot be independently confirmed.
Meanwhile, the CIA has withdrawn its top spy from Pakistan, amid threats to his life, US intelligence confirms.
The Islamabad station chief had been identified in a lawsuit linking him to drone strikes, and media coverage of the legal action led to his name appearing on placards during anti-US protests in the Pakistani capital.
US drone attacks in Pakistan's tribal region have increased under the presidency of Barack Obama, often occurring several times every week.
But the US now appears to be expanding its campaign to other parts of the tribal belt, as most of these attacks have been in the Waziristan region, says the BBC's Syed Shoaib Hasan in Karachi.
Drone attacks in Khyber are rare.
The first missile attack on Friday in the Tirah Valley is said to have taken place at 0800 local time (0300 GMT).
Seven Taliban militants died and 11 were injured when two vehicles were targeted in the Sandana area, a Pakistani security official told the BBC.
Those killed were militants from outside the Khyber tribal region, said the official.
Minutes later there was another attack in the Speen Drang area at a compound where pro-Taliban militants from the Lashkar-e-Islam group were holding a meeting.
At least 32 people, including senior leaders of the group, died, according to the official.
The Lashkar-e-Islam group is trying to enforce its hardline version of Sharia law in the area. A small number of its militants are involved in fighting Nato forces across the border in Afghanistan.
The third attack took place in the afternoon in the Narai Baba area, the official said.
"A compound was hit killing at least 11 militants," the official told the BBC. "All were from Swat and were taking refuge due to the military operation there."
On Thursday, at least seven more militants loyal to Taliban chief Hafiz Gul Bahadur died when several drone missiles demolished a house.
'UK militants' mystery
The BBC's Syed Shoaib Hasan in Karachi says Khyber is an unusual target for drone attacks, as it is not usually seen as a major militant sanctuary.
The Waziristan tribal area is believed to be the main haven for the leadership of the Taliban and al-Qaeda.
But with many militants having fled to other parts of the tribal belt due to drone strikes, the US now wants to target these new havens, says our correspondent.
It emerged this week that two white British al-Qaeda members had apparently died in a US drone raid in North Waziristan in recent days.
The Muslim converts, aged 48 and 25, were killed in a missile attack on a vehicle six days ago, said Pakistani officials.
They told the BBC the Britons' surnames were Stephen and Dearsmith.
There have been more than 100 attacks by pilotless US aircraft in 2010, most of them in North Waziristan.
Drone strikes are credited with killing some top insurgents, but are also blamed for civilian deaths.
The attacks have angered Pakistani public opinion. The country's government criticises such strikes, saying they merely fuel support for militants.
But analysts say Pakistani officials privately condone and probably provide intelligence for such strikes.
Pakistan's military has launched offensives in parts of the north-west, including the Swat Valley, but the insurgents continue to mount attacks.
The US military and the CIA do not routinely confirm that they have launched drone operations, but analysts say only American forces have deployed such aircraft in the region.