The IG police says sketches of the attackers will be drawn with the help of eye-witnesses to progress the case. He added that investigation of the deadly attack on law enforcers was underway.
Khwaja also claimed that the criminal group behind the attacked had also been identified.
Meanwhile, the counter terrorism department has called ten witnesses for testimony into the case. Of 10 eye-witnesses, four had seen the attackers from a close range.
The FIR of the attack has been registered against unidentified criminals. Initial investigation suggested that the weapon used in the assault bore resemblence to previous terrorism activities in the metropolis.
Motorcycle gunmen had shot dead seven policemen guarding a polio vaccination team in Karachi on April 20.
The interior of the police van was heavily soaked with blood, with an officer’s cap lying on the front seat.
Speaking to the media, provincial police chief Allah Dino Khawaja announced a $50,000 reward for the arrest of the gunmen, as well as $20,000 compensation to each of the victims’ families.
Attempts to eradicate polio have been badly hit by militant attacks on immunisation teams that have claimed more than 100 lives since December 2012.