QUETTA, Pakistan (AP) — Pakistani security forces launched a major operation before dawn Saturday to hunt down gunmen who hijacked two buses and killed at least 19 passengers in the country’s southwest, officials said.

In a statement, the country’s paramilitary Frontier Corps said 200 troops were taking part in the operation in the country’s restive Baluchistan province, the home of a long-running insurgency that has seen increasing violence in recent weeks.

Baluchistan Home Minister Sarfaraz Bugti said the violence began Friday night when the gunmen abducted 25 passengers and killed 19. He said authorities recovered the remaining six passengers, one of whom is in critical condition.

Bugti said the abductors initially captured 70 passengers but let around 50 flee.

Private satellite news channel Geo TV aired an interview with a man it identified as a survivor, who said the gunmen who attacked the buses wore security force uniforms. He said the gunmen separated passengers by ethnicity, ordering Pashtun people to stand in line while allowing Baluch passengers to flee.

“The gunmen lined up Pashtun passengers after checking their identity cards and then opened fire,” said the survivor, who the channel did not identify by name.

No group immediately claimed responsibility for the attack. However, Baluchistan is the scene of a low-intensity insurgency by Baluch nationalists, separatists and other groups demanding more autonomy and a greater share of the province’s gas and mineral resources. Similar attacks by Baluch nationalists have seen them let Baluch flee.

Elsewhere in Pakistan, a suicide bomber blew himself up Friday near a stadium in Lahore where a cricket match was underway between Pakistan and Zimbabwe, killing a police officer and wounding six, Information Minister Pervez Rashid told Geo TV.

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

No one immediately claimed responsibility for the suicide bombing, but the Pakistani Taliban, which has been at war with the government for years, has carried out past suicide bombings targeting civilians.

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