QUETTA, Pakistan — Pakistani police are still searching for gunmen who killed nine people after abducting them from a bus on a highway in the country's southwest. The same attackers had earlier killed two people and wounded six in another car they forced to stop.

The militant group Balochistan Liberation Army claimed responsibility for the attack on Friday night in Balochistan Province.

It said it had information from sources that spies in plain clothes were on the bus, according to a statement from the group. The gunmen killed the nine men after checking their ID cards to ensure they were intelligence officers.

The group offered no evidence to support the allegation that spies were on the bus. Authorities denied the allegation, saying the men were laborers heading to Iran.

Earlier on Saturday, Deputy Commissioner of Police Habibullah Mosakhail said the gunmen had set up a blockade, then stopped the bus and checked the passengers' ID cards. They took nine people with them, all from the eastern Punjab Province, and fled into the mountains, he said.

Police later recovered nine bodies under a bridge about 5 kilometers from the highway.

On Friday, the same gunmen had opened fire at a vehicle, killing two and wounding six, police said.

A search for the perpetrators was underway, Mosakhail said. The bus was heading from the provincial capital of Quetta to Taftan, a town bordering Iran.

PM's condemnation

Pakistan's Prime Minister Shehbaz Sharif condemned the attack, expressing his "deep sorrow and regret over this shocking incident".He offered his condolences to the bereaved families and said he stood by them in their hour of grief, a statement from his office said.

"The perpetrators of this incident of terrorism and their facilitators will be punished," Sharif said.

Abductions are rare in Balochistan, where militants usually target police forces and soldiers or infrastructure.

Although the government says it has quelled the insurgency, violence in Balochistan has persisted.

Authorities are also struggling to contain militancy in other parts of the country.

In the northwestern province of Khyber Pakhtunkhwa, the army said on Saturday that a "high-value terrorist ring leader" and two members of government forces were killed in an intelligence-based operation in Buner district.

Agencies via Xinhua