A boat carrying dozens of passengers and vehicles capsized and sank near the popular tourist island of Bali in Indonesia, local emergency officials said Thursday.

The ferry was carrying 53 passengers and 12 crew, as well as 22 vehicles, the Surabaya Search and Rescue Agency, which is based in Java, said.

Initial reports varied, but at least four people have died and another 31 have been rescued, according to the agency, with 30 people still missing.

What do we know about the incident?

The vessel, the KMP Tunu Pratama Jaya, sank at around 23:20 local time (15:20 UTC/GMT).

It departed from East Java's Ketapang Port shortly before 11 p.m. local time Wednesday, and sent a distress signal about 20 minutes later, said Wahyu Setiabudi, coordinator of the search and rescue post in Banyuwangi on Java island.

The ferry was headed for Gilimanuk Port in Bali, a 50-kilometer (30-mile) trip.

Search and rescue workers were deployed to the area of the vessel's last known location, but efforts were hindered by rough seas and inclement weather, Wahyu said.

Local media reported that the boat had issued a mayday call requesting urgent assistance because of an engine malfunction.

Why are maritime accidents common in Indonesia?

Ferries are a common mode of transportation in Indonesia, a vast archipelago of over 17,000 islands.

Maritime accidents are common in the country, where safety standards are poorly enforced.

A boat carrying 16 people capsized near Bali in March, killing one Australian woman and injuring one other person.

More than 150 people drowned when a ferry sank on Lake Toba on Sumatra island in 2018.

Edited by: Sean Sinico