Four terrorists were killed and four others arrested after a 12- hour gun battle at a naval base PNS Mehran in Karachi on Monday.

“Fake ID Cards with monogram of security forces were recovered from the four arrested terrorist,” Geo News reported. The terrorists were not in police uniform, report said.

More than ten terrorists entered the naval security base at 10:40 pm on Sunday and set two patrol planes on fire, government officials told local media. Search operations are still on.

“Thirteen security personnel have been killed and 14 were injured,” Pakistan Navy spokesman told local media.

Emergency has been declared across Karachi's hospitals after the attack, Indian Express reported.

In April, militants had attacked two naval buses killing seven people.