Protests were organised in the garrison city of Rawalpindi near Islamabad over sectarian clashes on Friday that left 10 dead.
The army took control of Kohat and Hangu in Khyber-Pakhtunkhwa province and a curfew was clamped in the cities following an attack on an imambargah or Shia prayer hall at Zargaranabad in Kohat district.
Police officer Mazhar Jaan was quoted by the Dawn newspaper as saying that unidentified persons attacked the imambargah this morning. Two policemen and a civilian were killed in an exchange of fire between two rival groups, he said.
Activists of the Ahl-e-Sunnat Wal Jamaat, a front for the banned Sipah-e-Sahaba, had organised a rally in Kohat city to protest the clashes in Rawalpindi.
In the face of mounting tensions, authorities imposed a curfew in Kohat and Hangu and the army took control of both cities.
In Rawalpindi, fresh protests were held after curfew was lifted this morning. Students of a seminary and traders gathered outside Raja Bazar at 11 am and shouted slogans against the administration.