Officials in the capital Islamabad said three people were killed and four injured in a gun fight at a local election campaign meeting in the northwestern tribal zone on Tuesday.
The clash took place in Wana, the main town in South Waziristan, where two journalists were shot dead and an AFP journalist injured by unidentified armed men on Monday night in a separate incident.
Faridullah Khan Wazir, a local leader who had convened the council election meeting, said the firefight between rival groups killed a man and his son as well as a passerby.
Pakistan's military launched a string of operations in the north-western region last year to track down al-Qaida-linked groups believed to have sneaked across the border from Afghanistan after the fall of the Taliban in late 2001.
Meanwhile, officials in the Baluch city Quetta said tribal rebels on Tuesday blew up a railway track and fired rockets at a telecommunication tower in the latest spate of violence in the region.
A section of people in Baluchistan
seek greater autonomy
Train services between Quetta and rest of the country were suspended after a section of the railway track was blown up near the town of Sibi, about 100km to the southeast late on Monday.
Officials said the track had been repaired, but train services remained suspended because of two more explosions in the area on Tuesday.
"We are checking whether the railway line has again been hit or the explosions occurred somewhere else," one official said.
Fear of attack
For the past few weeks trains have not been running at night in Baluchistan because of the fear of attacks.
Elsewhere in the province, rebels fired at least three rockets at a telecommunication tower in a remote area of Nushki, located around 120km southwest of Quetta.
"We are checking whether the railway line has again been hit or the explosions occurred somewhere else"
An unnamed official
"Two rockets missed the target. The third one landed inside our building, but it did not explode," said Mehboob Ali, an official of the Pakistan Telecommunication Company.
Baluch rebels have frequently attacked transport routes, power and telephone lines, and gas production facilities in recent weeks.
They seek greater autonomy for Baluchistan - the country's biggest, but poorest of the four provinces - and have sustained a low-level insurgency for decades, but have stepped up a campaign of violence in the past month.