Pakistani fighter jets have launched an assault on tribal areas near the Afghan border in an operation against Taliban fighters, flattening several houses and sending villagers fleeing from their homes, military sources and local residents have said.

Residents of North Waziristan, where many al-Qaeda-linked groups are based, said there were numerous civilian casualties.

A military spokesman told Al Jazeera that 15 fighters had been killed in the onslaught. The military said those killed were linked to bombings in a bazaar and a church as well as Sunday's attack in Bannu that killed 20 soldiers.

Tuesday's air strikes took place as domestic pressure grew on Prime Minister Nawaz Sharif to take tougher action against the Pakistani Taliban, following a string of attacks against security forces across Pakistan in the past week.

The attack on the Pakistani army convoy on Sunday prompted Sharif to cancel his trip to the World Economic Forum in the Swiss resort of Davos, and sparked speculation that a military operation was imminent.

In a second attack on Monday, a man on a motorcycle detonated his device at an army checkpoint in Rawalpindi. At least 13 people died in the explosion.

"This hadn't been planned before, and Pakistan air force fighter jets were called to hit hideouts of the militants involved in attacks on security forces," said one military official who spoke on condition of anonymity.

Tribal elder Malik Jan Mohammad in the Mir Ali area told Reuters news agency that 15 people were killed, while a Taliban source put the death toll at 27, including civilians.

Taliban hideouts

Military sources said fighter jets were only targeting hideouts of fighters in the area. Residents said the bombardment started overnight without any warning.

"We were all asleep when the planes started bombing the village," said Khyal Zaman, a tribesman from Esori village in the Mir Ali area.

"We had no idea what happened in the dark and those who survived came out of their homes in desperation along with children and started walking away into the open."

The assault comes after two attacks in two days claimed the lives of more than 30 people, many of them soldiers.