Police said that in a pre-dawn attack on Monday, militants dynamited a main gas pipeline located in the western bypass in the provincial capital Quetta and fled towards the nearby hills, a Press TV correspondent reported.
Following the attacks, security has been further tightened at the gas installations in Sui, Loti, Pir, Koh and Ouch.
No group has yet claimed responsibility for the attack.
The region has been hit by similar attacks in recent months.
The 2001 US-led invasion led to the Taliban spillover across the border into Pakistan's troubled Balochistan Province, leading to increased militancy there.