Militants had targeted the Pakistani navy dockyard in Karachi, seen here in a 2006 picture
The Pakistan navy says it fought off an attack on its Karachi dockyard in which two militants and a sailor were killed.
The gun battle on Saturday night is said to have lasted about six hours. A Pakistani Taliban spokesman said the group carried out the attack.
A low-ranking navy personnel member and two militants were killed, while six soldiers and an officer were wounded, the navy says.
In 2011, militants carried out a major attack at a naval base in Karachi.
A navy spokesman said four militants had been captured alive after Saturday's attack. Based on information which they provided, security agencies have detained collaborators from other parts of the country.
"No material loss took place," he said. The spokesman did not give further details about the nature of the attack or possible target.
Pakistan Taliban spokesman Shahidullah Shahid told the BBC the group carried out the attack.
He told AFP news agency that they had "support from inside the naval force for this attack" and would continue targeting security forces.
The BBC's Shahzeb Jillani in Karachi says security experts have long feared the possible penetration of jihadi groups into Pakistan's armed forces, especially the navy.
In recent years, the Pakistani Taliban have carried out a number of high-profile assaults on military installations. Besides the 2011 attack on the Mehran naval base in Karachi, they also stormed and briefly occupied the military's headquarters in Rawalpindi in 2009.
Militant attacks inside Pakistan have fallen sharply since June when an army offensive was launched in North Waziristan, which had been a Taliban stronghold.
BBC NEWS