JINAN -- Seven people have been rescued from a cargo ship that capsized off east China's Shandong Province early on Wednesday, the local maritime and fishery department said.

Rescue work is continuing but the total number of people aboard the ship is not immediately known.

The cargo ship, which authorities suspected had illegally carried passengers, capsized at around 5:00 a.m. about one nautical mile from the coast of Penglai, where it had begun its journey, a small city in Yantai. It was en route to Changdao (Long Island) County. The journey between the two locations normally takes about 40 minutes.

The seven rescued have been sent to hospital and are not immediately available for an interview.

An investigation has been launched.