Attackers ambushed a Pakistani army convoy today, killing 12 soldiers and wounding 22 more, as tribal elders tried to persuade encircled al Qaeda fighters to surrender.
The army, which says it has trapped hundreds of militants and their Pakistani tribal allies in rugged territory near the Afghan border, held fire to let a delegation of elders talk peace.
However, a convoy heading for the town of Wana to support the operation against the militants was ambushed by fighters with rockets.
"There were 12 dead and 22 wounded," one government official said.
There was no information on casualties among the attackers.
The operation , involving 5,000 troops, is the biggest Pakistan has ever waged in its semi-autonomous tribal area and is part of a major push to try and sweep foreign militants from the Afghan border region and catch al Qaeda chief, Osama bin Laden.
US forces are hunting on the other side of the border. The twin operations come amid heightened worldwide anxiety over al Qaeda attacks.
The fighting in the fiercely independent tribal region of South Waziristan erupted last week after security forces moved in to hunt al Qaeda suspects and their tribal allies.
Officials said some of the militants could have escaped through a series of tunnels connecting the mud-walled fortresses in the area, although others show no sign of giving up.
Pakistan had been coming under pressure from Washington for not doing enough to root out militants from its remote mountains.
Some analysts say two attempts to kill President Pervez Musharraf in December, blamed on al Qaeda, helped convince the government it was time to act tough.