KARACHI - A low-intensity blast outside naval airbase Faisal in Karachi left at least three officials wounded on Sunday evening, officials said.

Three security guards of Pakistan Air Force sustained injuries when unidentified attackers threw a grenade at the entrance to Faisal airbase in Karsaz area of Karachi. A spokesperson for PAF said it was a cracker blast.

The miscreants hurled a cracker outside the airbase around 10:18 PM, the spokesperson said, adding the security men standing on guard sustained minor injuries in the explosion. A vehicle was also damaged.

According to the SSP (East) the airbase was the apparent target of the attack as the grenade lobbed by unidentified assailants hit the boundary wall of the base and went off.

After the explosion, a massive contingent of law enforcers, including Rangers and police, rushed and cordoned off the area. The injured guards were rushed to a hospital and discharged after first aid treatment.

Arshad Janjua, station house officer for Shahrah-e-Faisal Police Station, said the attackers came on a motorcycle and lobbed a cracker near the main entrance to the airbase, and fled. He said nothing could be established before completion of investigations.

Initial reports said the moderate intensity blast was either an improvised explosive device or a crudely made cracker. Experts of Bomb Disposal Squad however confirmed the explosion was carried out through a locally manufactured cracker. Following the attack, tension simmered in the area. An investigation has been launched into the incident.

After the PNS Mehran base attack in May 2011, this was the second such attack on Faisal airbase. On February 5, 2013, unidentified assailants hurled two crackers in front of Sharah-e-Faisal airbase flyover, wounding a pedestrian.