An air force official says the wreckage of a Russian-made passenger jet that disappeared during a demonstration flight in Indonesia appears to have been spotted on the side of a volcano.

Maj. Ali Umri Lubis, of Atang Sanjaya Air base in Bogor, told MetroTV on Thursday that helicopters spotted what they believe is the plane on the side of a cliff on Mount Salak in West Java province.

He said it was at an elevation of about 1,500 meters (5,000 feet) but had no further details.

The Sukhoi Superjet-100 was carrying 48 people _ including potential buyers and journalists _ when it dropped off the radar just 21 minutes after takeoff Wednesday.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

JAKARTA, Indonesia (AP) _ Search and rescue teams scoured a dormant volcano's slopes in western Indonesia early Thursday for signs of a new Russian-made passenger plane that disappeared from radar while on a demonstration flight. The 48 people on board included potential buyers, diplomats and journalists.

Helicopters resumed a search suspended earlier because of bad weather. The Sukhoi Superjet-100 took off from an airport in Jakarta on Wednesday afternoon and radar lost it 21 minutes later. It was flying in drizzle near Salak mountain at the time.

Russia's first new passenger jet since the fall of the Soviet Union two decades ago has been widely considered the country's chance to regain a foothold in the international passenger plane market. The 75- to 95-seat plane was being shown off during a "Welcome Asia" tour that had already included stops in Myanmar, Pakistan and Kazakhstan.

The plane left Halim Perdanakusuma Airport in Indonesia's capital, Jakarta, at 2:21 p.m. (0721 GMT) Wednesday for what was supposed to be the second quick test flight of the day.

It dropped off the radar shortly after the crew asked air traffic control for permission to drop from 10,000 feet to 6,000 feet (3,000 meters to 1,800 meters), said Daryatmo, chief of the national search and rescue agency.

They didn't explain the change of course, he said. Though drizzling at the time, it was not stormy, and there was no obvious sign of trouble.

Cell phones of those on board were either turned off or not active.

"I saw a big plane passing just over my house," Juanda, a villager who lives near the 7,200-foot (2,200-meter) mountain, told local station TVOne.

"It was veering a bit to one side, the engine roaring," he said. "It seemed to be heading toward Salak, but I didn't hear an explosion or anything."

Dozens of family members spent the night at the airport, awaiting news about their loved ones. Many were crying. Some clung to young, sleepy children.

Windy Prisilla said her husband called her early Wednesday to say he was going on the Sukhoi test flight.

"He wanted me to meet him at the airport before they took off so we could have lunch together, but I told him I couldn't. I had to get the kids to school," she said, sobbing inconsolably as friends wrapped their arms around her.

"All I can do now is pray to God. I want him back home safely."

Sunarbowo Sandi, another official with the search and rescue agency, said around 800 people were taking part in the hunt for the plane, including soldiers, police and personnel with the local air force.

Some had worked through the night, though they were hampered by the rough and forested terrain.

They were focusing on three spots near the mouth of the volcano, at an elevation of around 2,000 feet, and along the northern slope.

"We're having trouble," said Sunaryo from PT. Trimarga Rekatama, the company that helped organize the event.

"Normally, a distress signal is automatically sent out by a sophisticated aircraft like the Sukhoi, which would have been detected by radars either in Jakarta, Singapore or Malaysia," he said.

"But... we've heard nothing."

Russia's aerospace industry was badly undermined in the economic turmoil following the 1991 collapse of the Soviet Union.

The Superjet _ developed by the civil aircraft division of Sukhoi with the co-operation with Western partners _ was being touted as a challenger to similar-sized jets from Canada's Bombardier Inc. and Brazil's Embraer SA.

It made its inaugural commercial flight last year.

With a relatively low price tag of around $35 million, the plane has garnered around 170 orders. And Indonesia, a sprawling archipelagic nation of 240 million people with a fast-growing middle class, was considered one of the biggest potential customers.

Kartika Airlines _ among dozens of airlines to have popped up in Indonesia in the last decade _ had been planning to buy 30.

People involved in those plans said they were waiting for the results of the investigation before reconsidering. Most wanted to know whether the problem was mechanical or pilot error.

Earlier officials said 50 people were on board the plane _ including potential buyers from several major local airlines, reporters and officials from the Russian Embassy.

But Sunaryo, who was partly responsible for the guest list, later revised the number to 48 saying a former cabinet minister and his son had to cancel at the last minute.

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Associated Press writer Jim Heintz in Moscow contributed to this report.