At least 24 militants were killed this week since Baloch separatists launched raids in a remote part of Pakistan's southwest, the military said Friday.

The group launched an attack on a compound of government facilities in Mach, about 200 kilometres from the Iran border in Balochistan province overnight on Monday.

"These terrorists were then hunted down in the ensuing sanitisation and clearance operations which have now been concluded after clearing and securing the area," a statement from the military's media wing said.

Four security personnel and two civilians were killed during the attack and subsequent raids.

The Balochistan Liberation Army (BLA), a banned ethnic Baloch outfit, claimed responsibility for the attack in a statement on social media.

In the build-up to the elections on Thursday, more than a dozen grenade and gun attacks have been reported in the province.

Pakistan's election commission said the elections would go ahead as planned, after calling an urgent meeting of security officials on Wednesday.

At least two candidates have been killed during the campaign -- not unusual in the South Asian nation where elections are marred by violence, with candidates and rallies targeted by militant groups as well as over personal vendettas.

Islamabad has for decades battled ethnic separatist factions in Balochistan, Pakistan's largest but poorest province which is rich in natural resources.

Locals say they do not get their fair share of wealth from the oil and gas reserves, with the region consistently ranking at the bottom of Pakistan's human development indicators.

Rights groups say a military crackdown on ethnic Baloch citizens includes enforced disappearances and extrajudicial killings.