Sixty pro-Taliban militants and 20 soldiers were killed in clashes in Pakistan's restive North Waziristan tribal region on Sunday. Security forces have launched a massive crackdown in retaliation for attacks on the military by rebels over the past few days.

Over 30 militants were killed and ten soldiers injured in clashes south of the town of Mir Ali after some 500 security force personnel backed by helicopter gunships and artillery launched an operation against militant hideouts in the region bordering Afghanistan, military spokesman Major General Waheed Arshad said.

Hours after the operation by the security forces began, militants ambushed a military convoy at Hassukhel in North Waziristan, killing at least 10 soldiers and injuring 12 others. Twenty militants were killed when soldiers retaliated, Arshad said, adding that the two sides were still exchanging fire.

In a separate incident, security forces arrested two militants in the same area.

Local residents claimed that four civilians, including three women and a child, were also killed in the clashes in the mountainous area.

The army launched the crackdown after the militants ambushed two military convoys using improvised explosive devices near Mirali town on Saturday, killing two soldiers and injuring 30 others. The operation was continuing till late Sunday, with security forces shelling militant hideouts in the mountains, reports said.

Arshad dismissed reports that the militants had kidnapped some soldiers in the area on Saturday, describing them as 'false propaganda' by the rebels.

Reports had claimed that pro-Taliban militants kidnapped at least 28 soldiers in the Spin Wam area of North Waziristan after attacking a military position with rockets and missiles.

Nearly 300 soldiers and paramilitary troopers have been abducted by militants in North and South Waziristan in recent moths, affecting the morale of security forces deployed in the area.

The militants gunned down three of the kidnapped soldiers in South Waziristan on Thursday and threatened to kill more of them to pressure the military to halt operations in the region. The region has witnessed an upsurge of violence since the militants scrapped a peace deal with the government in July after troops were deployed in the area.