A senior police officer said heavily-armed militants fired indiscriminately at a passing vehicle carrying CRPF troopers for law and order duties near Rainawari chowk of the old city, 4 kms from the city centre of Lal Chowk.
"Seven CRPF troopers were injured in the firing. The jawans were immediately evacuated to hospital for treatment. The condition of two is critical," the officer said.
Authorities rushed heavy reinforcements to the area, which has now been surrounded for searches to trace the two motorcycle-borne assailants who fired at the vehicle.
No group has yet claimed responsibility for the attack.
Hard-line separatist leader, Syed Ali Shah Geelani had called for a shutdown Wednesday to coincide with the alleged rape and murder of two women in south Kashmir's Shopian town in May 2009.