The northwestern Pakistani city of Peshawar was tense on Thursday following a suicide bomb attack in which three people were killed and 13 policemen injured.
The blast occurred near two police vans on the Ring Road in Peshawar City.
Following the explosion, incidents of gunfire have been reported on the GT road of the city. The authorities have beefed up security in Peshawar, Geo TV said.
Heavy contingents of police cordoned off the areas where firing incidents were reported, officials said.
Authorities said two motorcycle-borne riders first hurled a hand grenade at the police stationed on the Ring Road and then a suicide bomber blew himself up at the site, killing three people and injuring 13 policemen.
The injured were rushed to hospitals.
Meanwhile, Prime Minister Yusuf Raza Gilani has ordered an inquiry into the attack.