A Myanmar military plane carrying 116 people went missing on Wednesday between the southern city of Myeik and Yangon, according to the office of the army chief and an airport source.
In a statement posted to Facebook, commander-in-chief Min Aung Hlaing said the plane disappeared from radar screens at around 1:06 pm (0636 GMT) while flying at 18,000 feet. A search had been launched, it said.
Its last known position was west of 20 miles west of Dawei, the capital of Tanintharyi Region, where it had departed from earlier in the afternoon.
A Myanmar military plane carrying 104 people went missing on Wednesday over the Andaman Sea, sparking an air and sea search.
Four naval ships and two air force planes have been sent to search for the plane, which was flying at more than 18,000 feet when it went missing.
Dawei is a port town an hour's flight south of Yangon, Myanmar's commercial capital.
An airport source, who asked not to be named, said the plane was carrying 105 passengers and 11 crew. Whereas Gen. Myat Min Oo said the Chinese-made Y-8 aircraft was carrying 90 passengers — mostly families of military personnel — and 14 crew members when it went missing.
The plane was delivered in March last year and had 809 flying hours.
"We think it was a technical failure. Weather is fine there," an airport source told AFP, asking not to be named, adding there was no news of the plane so far.
Myanmar's military fleet has a checkered recent history of plane crashes.
All five crew died when an air force plane burst into flames soon after taking off from the capital Naypyidaw in February last year.
Three army officers were killed in June when their Mi-2 helicopter crashed into a hillside and burst into flames in south-central Bago.
The missing plane is a Y-8F-200 four-engine turboprop, a Chinese-made model still commonly used by Myanmar's military for transporting cargo.
The former military junta bought many of the aircraft from Myanmar's giant neighbor during their 50 years of isolated rule, when they were squeezed by Western sanctions.
A former executive at Myanmar's aviation ministry said it was one of China's most popular military and civilian transport aircraft.
A surge in demand for air travel as Myanmar opens up has stretched the impoverished country's aviation infrastructure, in particular in remote airports.
Commercial jets have also suffered frequent incidents.
The worst in recent years was in 2012 when an Air Bagan jet crash-landed in thick fog and burst into flames short of the runway at Heho airport, killing one passenger and a motorcyclist on the ground.