A Myanmar army aircraft with more than 100 people on board went missing Wednesday on a flight from southern Myanmar to the city of Yangon, the military and civil aviation officials said.

Gen. Myat Min Oo said the Chinese-made Y-8 turboprop aircraft left the coastal town of Myeik at 1:06 p.m (0636 GMT) heading north to Myanmar’s largest city of Yangon.

It lost contact while flying over the Andaman sea, about 20 miles (32 km) west of the town of Dawei, the military and civil aviation officials said.

“The military plane went missing and lost contact after it took off from Myeik, and now the military has started a sea and air search with naval ships and military aircraft and is preparing for rescue operations,” he said.

He said it was raining at the time, but not heavily.

“We don’t know what exactly happened to this plane after the loss of contact,” said Kyaw Kyaw Htey, a civil aviation official at Myeik airport.

Myeik, also known as Mergui, is a city in southeastern Myanmar on the Andaman coast. Much of the plane’s route would have been over the Andaman Sea.

He said the weather had been “normal” with good visibility when the plane took off.

The military has mobilized the air force and navy to search for the aircraft.