Tension gripped parts of the city late on Thursday following firing incidents and arson attacks apparently in an attempt to enforce a shutdown strike called for Friday by different political parties against power outages in the city, officials said.

They said the scattered incidents of firing and arson were witnessed in different localities that left some 8 people injured.

In the first of the incidents, a passenger coach came under an armed attack near Banaras Chowk that left three people injured.

Later, armed men in Saddar intercepted a Green Bus set on fire.

Intense firing incidents were also reported in New Karachi, Qasba Colony, Landhi, Old Sabzi Mandi, Sachal and parts of Gulistan-i-Jauhar.