JAKARTA, Indonesia (AP) — A boat carrying 20 Indonesian migrant workers sank on its way to Malaysia, and rescuers have found 10 survivors and were searching Thursday for nine missing. One body was recovered, officials said.

The boat began leaking and sank about an hour after leaving Rupat Island in the Bengkalis regency late Tuesday, rescue spokesman Kukuh Widodo said.

The 10 survivors, mostly from North Sumatra, were wearing life jackets, Kukuh said. They told police the trip was illegal and the workers undocumented.

According to the Indonesian government, there were 6,231 Indonesian migrant workers in Malaysia as of December 2019. Malaysia is one of the main destinations for Indonesian workers.

Boats and ferries are popular means of transportation in the archipelago nation with more than 17,000 islands. Accidents caused by overcrowding and poor safety standards are common.

In 2016, an overcrowded boat carrying 101 Indonesian migrant workers and their families home from Malaysia capsized in stormy weather off Batam Island, near Singapore, killing at least 60 people.

One of the worst ferry sinking occurred off Sulawesi island in 2009, killing more than 330 people.