Eleven survivors were found clinging to the skiff's wreckage and were taken to hospital in Mayotte, about 40 miles from Comoros.
"A boat coming from Anjouan, Comoros, which was trying to illegally reach the French island of Mayotte was wrecked on Tuesday November 24, involving the death of 21 passengers," the ministry said in a statement.
Tens of thousands of migrants have successfully reached Europe in recent years but thousands more are believed to have drowned or died of exposure in search of a better life.
