QUETTA: Gunmen opened fire on a bus in Pakistan’s southwestern province of Balochistan in a suspected sectarian attack on Tuesday, killing around 26 Shia Muslim pilgrims traveling to Iran, police said.

Four assailants attacked the bus carrying more than 50 pilgrims near Mastung town around 50 km (30 miles) from the provincial capital of Quetta.

“They opened fire on the bus from all four sides. Then they got into the bus and fired again,” a police official in Mastung said.

Three more people were killed when gunmen opened fire on an ambulance near Quetta as it headed to the attack site in Mastung.

Sunni Muslim militants loyal to al Qaeda and the Taliban have carried out high-profile attacks on members of Pakistan’s Shia minority in the past.

“Two vehicles intercepted the bus. Forced all the passengers off and opened fire. Many of them fled,” the driver of the bus, Khushal Khan, told reporters at the scene of the blast.

“They were eight to 10 men and they were carrying rocket launchers and Kalashnikovs.”

Some shoes of the victims were scattered in the area. Rescue workers removed bodies from the spot.

Sunni militants have stepped up attacks against Shias in Balochistan in recent months.

Ethnic Baloch militants have been waging a low-level insurgency in Balochistan for years for more autonomy and greater control over natural resources of the region.

Officials say there is no evidence linking them with militants.

Emergency was declared in hospitals in Quetta. The death toll is expected to rise.