Pakistani forces have been extending their operation in the north-west
At least 44 people have died in a series of clashes between government forces and Taliban militants in north-west Pakistan, the military says.
Those killed include 38 militants and six soldiers across North West Frontier Province, officials said.
The worst violence was in South Waziristan, where the army said it was clearing the way for military convoys ahead a full-scale offensive.
The area is the stronghold of the Taliban leader, Baitullah Mehsud.
The reports from the army are hard to verify because the region is inaccessible to the media.
In South Waziristan, 32 militants were killed as the army used helicopter gunships and artillery fire to clear a key route for military convoys, an army statement said.
The military has said it wants to destroy Baitullah Mehsud's organisation and eliminate him.
On Friday, Pakistani war planes bombarded targets in the area as the military prepared its campaign.
Maj Gen Sajjad Ghani shows reporters an abandoned Taliban camp
Our correspondent says the Waziristan operation is expected to be the toughest yet for the Pakistani army, but many of its resources are tied up in the Swat valley.
There, a convoy was ambushed while on its way back to base, a military spokesman said.
The militants were able to get away, while several soldiers were killed and injured, he said.
The attack comes a day after Pakistan's defence minister said that Swat operation was nearly over, and that people displaced by the fighting could begin returning home.
On Saturday, Maj Gen Sajjad Ghani was quoted as saying that there were only "pockets of resistance" left in Swat.
The militants also conducted a deadly raid on another convoy in the neighbouring Bajaur tribal region.
According to security officials, the dead included a Pakistan army officer, while there were no reported casualties on the side of the militants.
The army says it has killed almost 1,500 militants in and around the Swat valley since April. About two million people have been displaced.
The fighting in the Swat valley began two months ago when Pakistani Taliban forces expanded their operations into districts only 60 miles from the capital, reneging on an earlier peace deal.
The continued attacks in the region have led to fears that the military could be spreading itself too thin, our correspondent says.