Islamabad, Pakistan (CNN) -- Gunmen shot dead five people, including four prostitutes, in Pakistan's troubled Balochistan province Thursday morning, police said.

Elsewhere in the province, a car bomb blast killed 12 people, including six police officers.

Awais Ahmed, the district police officer for the town of Sibi, said four gunmen on two motorcycles opened fire at a brothel in the town.

He said four prostitutes and a taxi driver were killed in the attack. Two other women were seriously wounded.

The second incident - the car bomb blast -- took place in the provincial capital of Quetta.

Deputy Inspector General Syed Ahmed Mobeen said the attackers used a remote-controlled device to trigger the bomb when a police vehicle was passing by.

The strength of the blast damaged nearby shops and houses. In addition to the deaths. the explosion wounded 21 others, Mobeen said.

No group immediately claimed responsibility for either incident. But suspicion immediately fell on Baloch insurgents operating in the area.

Militants in Balochistan, a province rich in natural gas, have been fighting Pakistani military forces for self-rule. For years, they have complained that the government has paid little attention to them and their economic needs.