A South Korean naval unit has captured and released suspected pirates in Somali waters after receiving a distress call from a Bahaman vessel.

The Joint Chiefs of Staff says the Cheonghae Unit received the distress call around 10:15 Tuesday night, Korean time, from the vessel cruising 117 kilometers southwest of Yemen.

The unit quickly dispatched a Lynx helicopter, three boats and 30 soldiers to the site, firing a series of warning shots to repel the suspected pirates from boarding the commercial vessel.

The Cheonghae Unit then received an order from the Combined Forces Maritime Component Command to search the pirate ship. The Korean team, in its first such boarding operation, took control of the ship, and the seven pirates aboard surrendered without resistance.

During the search of the ship, the team found a knife and empty rifle cartridges.

Cheonghae let the pirates go free after issuing warnings.