NONGSA, Indonesia (REUTERS) - A boat carrying 93 Indonesian migrant workers from Malaysia sank off an Indonesian island on Wednesday (Nov 2), killing 18 of them, police said.

The boat set sail from the southern Malaysian state of Johor and was headed towards Indonesia's Batam island, just south of Singapore, the Indonesian national disaster mitigation agency said in a statement.

The boat crashed into a reef after being hit by big waves and strong wind, and sank at around dawn, the disaster agency said.

There were 39 survivors.

A helicopter would be sent out to search for bodies, the region's police chief, Sam Budigusdian, told reporters. A baby was among the 18 confirmed dead, he said.

Zainul Arifin, one of the survivors who worked at an oil palm plantation in Malaysia, said he was sitting at the back of the boat when sea water started coming aboard. "I had to jump off and start swimming," Arifin told Reuters in the port town of Nongsa on Batam.

Many Indonesians work in Malaysian factories and plantations.

Boat accidents are common in Indonesia, a sprawling archipelago of more than 17,000 islands.