Missiles fired by a suspected US drone have killed at least six fighters in Pakistan's North Waziristan province, near the Afghan border, security officials say.
The attack targeted a compound used by fighters in Spalga village near Miranshah on Thursday, the officials said.
The US says Pakistan's tribal belt provides sanctuary to Taliban fighting in Afghanistan, al-Qaeda groups plotting attacks on the West, Pakistani Taliban fighters and other armed groups.
A salvo of missiles hit a house in Spalga about a week ago as well, killing nine people, including some Pakistani Taliban fighters, intelligence officials said.
The area is dominated by Hafiz Gul Bahadur, a prominent commander focused on fighting foreign troops in Afghanistan.
President Barack Obama last month confirmed for the first time that US drones target Taliban and al-Qaeda fighters on Pakistani soil, but American officials do not discuss details of the covert programme.
The New America Foundation think-tank in Washington says drone strikes in Pakistan have killed between 1,715 and 2,680 people in the past eight years.
The attacks have angered the Pakistani public, since many civilians have been killed in the raids.
Pakistani officials regularly denounce the strikes as a violation of the country's sovereignty, but the government is believed to have provided support for the programme in the past.
However, Yousuf Raza Gilani, Pakistan's prime minister, told Al Jazeera in an interview broadcast on Saturday that his country had not given permission for such attacks.
"First of all, I want to inform you that we did not allow or give permission to fly drones from Pakistan," Gilani said.
"Drones are counter productive and we have discussed it thoroughly with the US administration."
Gilani said the "collateral damage" from drone attacks was counter productive because it undermined his government's efforts to separate tribes from fighters, and also violated Pakistan's sovereignty.