Wellington, AUg 6 (DPA) A sea and air search was under way Thursday for 27 people missing following the sinking of an inter-island ferry off the South Pacific Island of Tonga.

New Zealand’s rescue coordination centre is overseeing the rescue effort, and an airplane is searching the area. Three vessels, including a Tongan naval boat, are assisting with the search, the centre said in a statement.

The centre launched the response late Wednesday, after receiving a distress call just before 11 p.m. Wednesday in New Zealand. It received a distress beacon from the vessel a few minutes later.

The vessel, the Princess Ashika, was bound from Tonga’s capital Nuku’alofa to the small island of Ha’afeva, inhabited by about 300 people.

The centre says the ferry sank about 46 nautical miles (86 km) northeast of Nuku’alofa.

The cause of the ferry sinking was unknown. Weather in the area is moderate with 25 knot winds and a swell of two to three metres, which is forecast to ease. Water temperature is approximately 25 degrees Celsius.