Twenty-eight people, mostly women and children, were killed as a trailer carrying a wedding party hit an anti-tank mine Friday morning in Pakistan's restive southern province of Balochistan, officials said.

"We know that 28 people died and seven were injured when the tractor-trolley carrying them hit at least one anti-tank mine at Rakhni (about 300 km east of the provincial capital Quetta).

"There were women and children in the vehicle and we are trying to get details of how many," Raziq Bugti, a spokesman for the Balochistan provincial government said.

Bugti said the injured were being shifted to Dera Ghazi Khan city in the neighbouring province of Punjab, while paramilitary troops have sealed off the site of the explosion.

He blamed the attack on "terrorist" tribal militants who are waging an insurgency to win more autonomy and a greater share of the gas-rich region's vast natural resources.

"The government of Balochistan condemns this act of sabotage in which innocent people were killed. Those behind the attack are terrorists and we are dealing with them with an iron hand," he added.