JAKARTA, Indonesia (CNN) -- Thick fog and steep, mountainous terrain forced rescuers to halt their efforts to reach the wreckage of a Russian jetliner that crashed on a demonstration flight in Indonesia, the country's state news agency reported Thursday.
The Sukhoi Superjet 100 came to rest on the side of Mount Salak, a volcano south of Jakarta, Vice Marshal Daryatmo, head of the National Search and Rescue Agency, told the Indonesian news agency Antara. Efforts to reach the wreck are expected to resume Friday morning, said Daryatmo, who like many Indonesians uses only one name.
"We have identified the crash coordinates, but our personnel have not yet arrived at the location," Antara quoted Daryatmo as saying. "However, because there is thick fog covering Mount Salak and the tilt of the cliff is 85 degrees, the evacuation process has been halted until tomorrow morning."
The Russian Investigative Committee said 48 people were on board the plane, including eight Russian crew members. But the Russian news agency RIA-Novosti said the number was 45, citing Sukhoi Civil Aviation President Vladimir Prisyazhnyuk as saying three of the people on the passenger list did not board the flight.
The wreckage was spotted at an elevation of about 5,800 feet (nearly 1,800 meters). Gagah Prakoso, a spokesman for the rescue agency, said the authorities hope to start removing bodies from the area by helicopter Friday, and there has been no sign that anyone survived.
Daryatmo said the Sukhoi logo had been identified amid the wreckage of the plane, which disappeared off radar screens Wednesday. An image released by the Indonesian military showed bits of debris strewn across a patch of steep mountainside that had been stripped bare of the thick surrounding vegetation.
The cause of the crash remained unclear. The Russian Investigative Committee said it had launched a criminal probe into possible safety violations.
The plane was on a demonstration flight for Indonesian Ministry of Transportation officials and representatives of Indonesian airlines, the Russian Embassy in Jakarta said before the crash.
Indonesia's Sky Aviation signed a $380 million deal in 2011 to buy 12 Sukhoi Superjet 100s, and press reports said a number of Sky employees were on the plane that went down. Sukhoi employees are also among the missing.
It was the first crash of a Sukhoi Superjet 100, RIA-Novosti said.
The plane was on its second demonstration flight Wednesday when it lost contact with air controllers at Jakarta's Halim Perdanakusuma Airport.
"The first demonstration flight in the morning went smoothly. There were no problems," said Sunaryo, an official with Sukhoi's Indonesian agent, Trimarga Rekatama, who also uses only one name. On the second flight, the plane began making its descent but vanished from radar screens at 6,200 feet in a mountainous area.
The plane lost contact with air traffic controllers at 2:12 p.m., 21 minutes after taking off, said Daryatmo, the rescue agency chief. Two helicopters were immediately sent out to search for the plane but had to return to their bases because of strong winds and unpredictable weather.
The Sukhoi jet arrived in Jakarta as part of a demonstration tour of six Asian countries. It had been to Myanmar, Pakistan and Kazakhstan, and was scheduled to visit Laos and Vietnam after Indonesia, RIA-Novosti said.
Sukhoi manufactures military aircraft and is known especially for its fighter jets. Its civilian aircraft is narrow-bodied with a dual-class cabin that can transport 100 passengers over regional routes. It flew its maiden flight in 2008.
In March, a Superjet 100 operated by Russia's Aeroflot Airlines was forced to abandon its flight to Astrakhan, Russia, and return to Moscow because of problems with the undercarriage, according to RIA Novosti.
A similar defect in another Aeroflot-operated Superjet 100 plane had to be fixed in Minsk in December. Russia's state-run United Aircraft Corp. said the defect did not affect passenger safety.