A car bomb has exploded in a bazaar in southwestern Pakistan, killing at least three people and wounding 24 others, police officials have said.

Saturday's attack took place when a vehicle carrying security forces was passing through a bazaar near Quetta, the capital of southwestern Baluchistan province, senior police officer Abdur Razzak Cheema said.

The dead included a paramilitary soldier and two civilians, Cheema told the Associated Press news agency.

The bomb was planted in a car parked at the roadside, according to a local bomb disposal squad official. 

"Nothing is left of the car, except the engine," the official said. "The explosive material was placed between the back seats and the boot of the car, which was triggered off by remote control. The target was the Frontier Constabulary convoy. They targeted the law enforcing agencies." 

No group immediately claimed responsibility and authorities said they were still investigating.

Baluchistan is Pakistan's largest province and it has been the scene of low-scale fighting for several years.

Separatists in the region often attack security forces and officials to pressure the government into allocating more wealth from resources such as gas and oil that are extracted from the province.

Source: Al Jazeera and agencies