China has delivered six of its Z-9 helicopters, equipped for anti-submarine operations, to Pakistan. This means the choppers are fitted with radar, dipping sonar and lightweight torpedoes. This model (the Z-9EC) can probably also carry the new air launched anti-ship missile, the TL-10, that China introduced last year, specifically for its Z-9 naval helicopter.
The missile was apparently developed in cooperation with Iran (which calls it the Kosar). The TL-10 is a 240 pound missile, with a 65 pound warhead. It has a range of about 18 kilometers. The TL-10 has been in use for a few years, and the latest version, the TL-10C is believed to have a fire and forget guidance system (based on onboard radar). The TL-10 can be lethal for smaller (under 500 tons) ships, but can do a lot of damage to larger ships.
The Z-9 is a license built version of the French AS 365N Dauphin. It's a four ton helicopter with a two ton payload. China has built over 200 of the Z-9s and many have been armed (with twin 23mm cannon, torpedoes, anti-tank missiles and air-to-air missiles.) The Z-9D, armed with four TL-10 missiles, while the Z-9EC simply has anti-submarine equipment installed instead.