Authorities in north-west Pakistan say Sunni and Shia Muslims are continuing to exchange gunfire, with five people killed in the latest clashes
Another five were reported hurt in the violence in Chardewar in the Kurram tribal agency near the Afghan border.
The number of people killed in a week of violence in the area has now passed 40, with over 70 hurt. However, local tribesmen say the toll is much higher.
The main town of the area, Parachinar, is under a curfew for a sixth day.
A local official told the BBC that the latest fighting was concentrated in three to four villages near the border.
A 40-member delegation of tribal elders has now reached Parachinar to try to broker a peace.
Army helicopter gun ships have been seen in the Parachinar area, but local residents accuse the government of failing to take action in the initial days of the outbreak of violence.
Trouble began last Friday when unidentified people began shouting anti-Shia slogans near their mosque.
The apparent reason was tension over a rally organised by Sunnis to celebrate the birthday of the Prophet Muhammad.
Shias accuse Sunnis of using abusive language against them in the rally.
Officials said that at least 40 people were killed and dozens wounded in two days of clashes.
Sectarian Clashes Leave 49 Dead, 115 Hurt in Pakistan