At least 30 people died after their boat sank off the Indian Ocean archipelago of Comoros, a rescue official said Tuesday.

"At the moment the death toll stands at 30 and 50 survivors," Mouigni Daho, the head of the centre for rescue operations and civilian protection, told AFP.

The accident occurred Monday night to the south of the Comoros' main island of Grande Comore where the boat had left for the archipelago's other island of Anjouan.