Sources said some activists of the group had gathered at Napura and set up hurdles on the road, where a Majlis-i-Aza was to be held. Police said as they tried to remove the hurdles, the activists hurled stones at them and opened fire.

"The police and the FC resorted to retaliatory fire. It is not clear whose firing caused the injuries," a police official said.

The injured, Asim Wali and Ehtesham, residents of Napura, Basin, were taken to the district headquarters hospital.

Tension gripped the city after the incident, all the markets were closed and the traffic came to a halt.

Speaking at a protest rally at Hunza Chowk, Jama Masjid Khatib Maulana Qazi Nisar alleged that every year the participants of the Muharram procession at Napura raised provocative slogans, which led to tension.