No one immediately claimed responsibility for Friday's attacks in Baluchistan province, where ethnic Baluch nationalist fighters often target government buildings, railway tracks and paramilitary forces as part of a campaign to get more royalty payments for resources extracted in their areas.
The fighters also oppose plans by the central government to build new military garrisons in Baluchistan, a mineral-rich but otherwise impoverished province of which Quetta is the capital.
Tension has been on the rise in Baluchistan since Pakistani security forces backed by helicopter gunships dismantled alleged separatist hideouts in Kolhu, east of the provincial capital, earlier this month.
Tribal elders say the raids left dozens dead, including innocent women and children, a charge the authorities deny.
In the latest attacks, assailants shot and killed two securitymen as they drove through Khuzdar, a town 300km southeast of Quetta, said Rahmat Ullah Hasni, a local police official.
Two rockets also slammed near a camp of government soldiers in Kolhu, about 300km east of Quetta, said Lieutenant-Colonel Hassan Jamil, spokesman for the Frontier Corps, adding no one was injured.
He said restive tribesmen were to blame for the attack. Hours later, tribesmen attacked a Frontier Corps post in Dera Bugi, triggering a shootout that left one attacker dead, said Abdul Samad Lasi, an official.
Baluch nationalists want a bigger
share of the revenue from gas
He gave no details about the clash in Dera Bugti, where the country's main gas pipelines are located.
Also on Friday, a bomb damaged a wall of a power grid station in Hub, 700km southeast of Quetta, said police official Jamil Ahmad.
He didn't say who carried out the attack, but the Baluchistan Liberation Army - a group that claims to speak for the rights of Baluchistan - has claimed responsibility for attacks in recent weeks in Kolhu and elsewhere.
On Thursday, fighters detonated a bomb at a barber shop in Naushki, 200km southwest of Quetta, said Arif Mengal, the regional police chief.
He said the owner of the shop and two other people were injured.
Meanwhile, Pervez Musharraf, the Pakistan president, has said, without naming India, that the statement by a neighbouring country about the situation in Baluchistan is intriguing, according to the Press Trust of India.
"We know who is financing and supplying weapons," Musharraf said on Thursday in Lahore in an address to the Council of Pakistan Newspapers Editors.
New Delhi had earlier this week noted with concern the spiralling violence in Baluchistan and heavy military action there and asked Pakistan to exercise restraint and address the grievances of the people of the region through peaceful discussions.
Musharraf called India's remarks
about Baluchistan intriguing
Terming the comments as unwarranted, Pakistan accused India of interfering in its internal affairs.
With regard to the Indo-Pak peace process, Musharraf said there was no doubt that Pakistan-India relations were at their all-time best. However, it was also true that there was not enough progress on Kashmir, he said.
Musharraf said confidence-building measures had been moving ahead and Pakistan was trying to speed up the process of dispute resolution as well.