A Russian Sukhoi Superjet 100 with at least 44 people aboard has gone missing on a demonstration flight in Indonesia.
The plane disappeared from radar screens during a flight from Jakarta meant to last 30 minutes, a blogger with the Sukhoi delegation said.
Helicopters were dispatched to look for the jet, thought to have been flying near a mountain, Sergey Dolya said.
Emergency services confirmed a Sukhoi plane was missing.
The plane, which took off at 07:00 GMT, is believed to have had about four hours’ fuel aboard.
Gagah Prakoso, spokesman for Indonesia’s national search and rescue agency, said 46 people had been aboard the plane, which vanished from radar near Bogor, a city in West Java province.
He said it was unclear who was on board because they were people invited by Sukhoi, but they were “likely to be reps of Indonesian airlines”.
Sergey Dolya tweeted that there were 44 people aboard, eight of them Russians.
The plane took off from east Jakarta’s Halim Perdanakusuma airport, which is used for some commercial and military flights, at 14:00 (07:00 GMT), the Indonesian search and rescue agency spokesman said.
“At 14:50 it dropped from 10,000ft [3,000m] to 6,000ft,” the agency told AFP.
Herry Bakti, head of the transport ministry’s aviation division, said the aircraft had been on the second of two demonstration flights, and those on board were invited guests.
The Russian embassy in Jakarta said in a statement earlier this week that a Sukhoi Superjet 100 demonstration would take place in Jakarta on Wednesday, AFP added.
The embassy could not be immediately reached for comment.
The Superjet, a mid-range airliner that can carry up to 100 people, is military plane-maker Sukhoi’s first commercial aviation plane.
It was created by a joint venture, majority-owned by Sukhoi, with Italy’s Finmeccanica and a number of other foreign and Russian firms also involved.
Gagah Prakoso said Sukhoi had been offering the Superjet to Indonesian airlines.