Update | 10 missing as boatload of illegal 'gamblers' from mainland China capsizes

About 10 people are missing after a speedboat believed to be carrying illegal visitors on a gambling trip from the mainland capsized off Macau early on Friday.

Mainland and Macau authorities launched an air and sea search-and-rescue operation after the boat overturned about 500 metres off the Grand Coloane Resort before dawn.

Four men and two women were picked up by customs and police officers.

The six included an alleged snakehead who was caught as he tried to swim back to Zhuhai , said Leung Wa-kan, head of Macau customs' marine patrol division. The other five swam ashore or were washed up on the beach. One of them was taken to hospital for examination.

Leung said they told rescuers there were 17 or 18 people on board the 7-metre speedboat, and that three of them were snakeheads.

He added that the other two snakeheads and three other passengers were believed to have swam ashore and fled before officers arrived.