Geo News channel also reported that a four-engine aircraft was destroyed in the daring attack at Pakistan Air Force's (PAF) Faisal airbase which also houses PNS Mehran, the naval air station.
Terrorists numbering between 12 and 15 were reported to be involved in the attack in the highly secured area and were believed to be holed up inside late in the night. A Pakistan Navy spokesman said, four people were killed attack by terrorists on PNS Mehran in Karachi.
The spokesman didn't identify the dead but television channels reported they included a foreigner. The terrorists targeted PNS Mehran where some Chinese engineers were engaged in work within the Faisal airbase, at about 10:40 pm, sources said.
The nature of the blasts could not be immediately ascertained. Samaa television channel reported that between 12 and 15 terrorists were holed up in the base and were engaged in heavy gunfire with security forces. Geo television reported that five people have been taken to hospital for treatment including a foreigner.
Interior Minister Rehman Malik confirmed that a group of terrorists had attacked the airbase. The terrorists were still within the airbase and naval commandos and paramilitary Pakistan Rangers were deployed to counter them, he told the media.
"Terrorists have attacked the Pakistan Naval Mehran base and the terrorists are still in the base and have been engaged by our forces," Malik said. "We have dispatched Naval commandos and para-military rangers to the base to tackle the situation," Malik said.
He said according to initial reports at least four explosions had taken place in the base. Dawn News channel quoted witnesses as saying that theyhad heard up to five blasts. Heavy firing continued over 20 minutes after the first blast occurred.
"Yes I can confirm explosions have taken place in the PAF faisal base and there is an exchange of firing going on.Security and law enforcement agencies have surrounded the area," Sharfuddin Memon, the advisor to the Sindh interior minister said.
The high-security area houses the PA's Southern Air Command, Air War College and museum as well as PNS Mehran, the main naval air station in Karachi. Footage on television showed ambulances rushing to the airbase as security guards cordoned off the area.
Flames and thick smoke billowed into the sky from an object burning near a four-engine aircraft. No group claimed responsibility for the attack, which came 20 days after al Qaeda leader Osama bin Laden was killed in a US raid on the garrison city of Abbottabad.
The Taliban and al-Qaeda have vowed to avenge bin Laden's killing by carrying out attacks in Pakistan and the US. The high-security area where the attack occurred houses the PAF's Southern Air Command, Air War College and museum as well as PNS Mehran, the main naval air station in Karachi.