Pakistani security forces have launched a major operation to hunt down gunmen who hijacked two buses and killed at least 19 passengers before fleeing.

Baluchistan Home Minister Sarfaraz Bugti said the violence took place in the south-western province on Friday when the gunmen abducted 25 passengers and killed 19.

He said yesterday that the authorities had recovered the remaining six passengers, one of whom is in critical condition.

Baluchistan is the scene of an insurgency by Baluch nationalists, separatists and other groups demanding more autonomy and a greater share of the province’s gas and mineral resources.

Around 20 armed men hijacked the two buses, and let around 50 passengers go.They took their six hostages into the mountains where security forces surrounded and fought them.

Elsewhere in Pakistan, a suicide bomber blew himself up near a stadium in Lahore where a cricket match was being played between Pakistan and Zimbabwe.

Information minister Pervez Rashid said the bomber had tried to get closer to the stadium but was stopped by police.

The bomber then detonated his payload, killing a police officer and wounding six others.

Police had initially said the explosion, which was heard during the match, was caused by an electric transformer nearly a mile away from the Gaddafi Stadium.

No-one immediately claimed responsibility for the suicide bombing, but the Pakistani Taliban has carried out past suicide bombings targeting civilians.