A Boeing 737 operated by Sriwijaya Air has gone missing shortly after take-off from Indonesian capital Jakarta.
More than 50 people are believed to have been on board the passenger plane at the time of the incident.
The aircraft lost contact en route to Pontianak, located in the West Kalimantan province of the country, officials said.
Pictures of what seemed to be aircraft debris appeared on TV and social media, while the transport ministry said search and rescue efforts were under way.
Last contact with the plane, with the call sign SJY182, was made at 14:40 local time (07:40 GMT).
The usual flight time to Pontianak, situated on the west of the island of Borneo, is an hour-and-a-half.
According to registration details, the plane is a 26-year-old Boeing 737-500.
Sriwijaya Air, a local budget airline which flies to Indonesian and other south-east Asian destinations, said it was still gathering information about the flight.
The plane is not, however, a Boeing 737 Max, the model involved in two major crashes in recent years.
The first of those, in 2018, involved an Indonesian Lion Air flight which crashed into the sea about 12 minutes after take-off from Jakarta killing 189 people.