Six militants were killed in an exchange of fire with security forces during an operation in Mach area of Bolan district, 70 km from the provincial capital of Quetta.
Two more militants were killed by security forces when the rebels attacked a Frontier Corps check post in Ispilanji area of Quetta, officials said.
Officials said the six militants killed in Mach were linked to an attack on Tuesday that killed 14 people, including security personnel. The militants had stopped vehciles at a fake check post and shot dead people after pulling them off buses.
Officials said a suspect was arrested and a cache of weapons and ammunition was seized.
In yet another incident, a roadside bomb blast killed Baloch tribal leader Zra Khan and wounded two of his guards in Dera Bugti district. The remotely detonated bomb destroyed Khan's car.
Several nationalist groups are engaged in an insurgent movement in Balochistan. They have been waging a violent campaign for more autonomy and a greater say in the exploitation of the province's abundant natural resources.