ahrik-e Taliban Pakistan (TTP) has claimed responsibility for a militant attack on a key naval base in the southern port city of Karachi.
The attack comes weeks after Pakistani militants pledged to avenge the killing of al-Qaeda leader Osama bin Laden.
The banned militant group said on Monday the raid was to avenge bin Laden's killing by US Special Forces on Pakistani soil in early May.
"It was the revenge of martyrdom of Osama bin Laden. It was the proof that we are still united and powerful," Reuters quoted a militant spokesman as saying.
The militants set off several high intensity explosives and destroyed two surveillance aircraft. Fighting continued into Monday morning.
Security forces have reportedly arrested four militants. The number of militant casualties is yet unknown.
Despite an offensive by the Pakistani government against pro-Taliban militants, they have spread their influence in various regions, killing people and security forces every day.
More than 4,000 people have died in bomb attacks across Pakistan since 2007, reports say.
Thousands of Pakistanis have been killed since former military ruler Pervez Musharraf joined the US-led war on terror following attacks on New York and Washington on September 11, 2001.
The US invaded Afghanistan with the official objective of curbing militancy and bringing peace and stability to the region, however, after nine years the region remains unstable and militancy has expanded towards Pakistan. Press TV
