Red and white debris spotted off the coast of Indonesia's part of Borneo island is likely to be part an AirAsia plane carrying 162 people which is presumed to have crashed two days ago, an Indonesian transport official said on Tuesday.

 Family members of passengers onboard missing AirAsia flight QZ8501 pray at a waiting area in Juanda International Airport, Surabaya, Indonesia, December 30, 2014.

Media quoted an air force official as saying a suspected body, luggage and a life vest were among the debris.

"As we approached, the body seemed bloated," said First Lieutenant Tri Wibowo, who was on board a Hercules during the search operation, was quoted by the Kompas.com website as saying.

The sighting of the body was not confirmed.

Indonesia AirAsia's Flight QZ8501, an Airbus A320-200, had sought permission from Indonesian air traffic control to ascend to avoid clouds just before it went missing early on Sunday on a flight from the Indonesian city of Surabaya to Singapore.

"The debris is red and white," Djoko Murjatmodjo, acting director general of air transportation at the transportation ministry, told reporters. "We are checking if it's debris from the aircraft. It's probably from the body of the aircraft."

Based on the size and coloring of the debris, it was likely to be part of the missing jet, Murjatmodjo added.

AirAsia planes are painted red and white.

There have been no confirmed sightings of any wreckage of the missing plane. Most of those on board were Indonesian.

Indonesia's Kompass TV showed pictures of what looked like large, angular objects floating in the sea. The largest appeared to be several meters long.

Earlier, Indonesian officials said the search area in the Java Sea between the islands of Sumatra and Borneo would be expanded.

About 30 ships and 21 aircraft from Indonesia, Australia, Malaysia, Singapore and South Korea were searching up to 10,000 square nautical miles on Tuesday, officials said.

The U.S. military said the USS Sampson, a guided missile destroyer, would be on the scene later in he day.

COULD PLANE HAVE STALLED?

The plane, which did not issue a distress signal, disappeared after its pilot failed to get permission to fly higher because of heavy air traffic, officials said.

Pilots and aviation experts said thunderstorms, and requests to gain altitude to avoid them, were not unusual in that area.

The Indonesian pilot was experienced and the plane last underwent maintenance in mid-November, the airline said.

Online discussion among pilots has centered on unconfirmed secondary radar data from Malaysia that suggested the aircraft was climbing at a speed of 353 knots, about 100 knots too slow, and that it might have stalled.

The plane, whose engines were made by CFM International, co-owned by General Electric and Safran of France, lacked real-time engine diagnostics or monitoring, a GE spokesman said. Such systems are mainly used on long-haul flights and can provide clues to airlines and investigators when things go wrong.

Three airline disasters involving Malaysian-affiliated carriers in less than a year have dented confidence in the country's aviation industry and spooked travelers across the region.

Malaysian Airlines Flight MH370 went missing on March 8 on a trip from Kuala Lumpur to Beijing with 239 passengers and crew on board and has not been found. On July 17, the same airline's Flight MH17 was shot down over Ukraine, killing all 298 people on board.

NO FOUL PLAY SEEN

On board Flight QZ8501 were 155 Indonesians, three South Koreans, and one person each from Singapore, Malaysia and Britain. The co-pilot was French.

AirAsia said it planned to fly relatives of the missing over the search area on Wednesday.

U.S. law enforcement and security officials said passenger and crew lists were being examined but nothing significant had turned up and the incident was regarded as an unexplained accident.

Indonesia AirAsia is 49 percent owned by Malaysia-based budget carrier AirAsia.

The AirAsia group, including affiliates in Thailand, the Philippines and India, had not suffered a crash since its Malaysian budget operations began in 2002.

India is waiting to know what went wrong with the missing plane and will investigate if AirAsia India is following all safety procedures, a senior Indian aviation ministry official told Reuters. AirAsia India, a joint venture of the Malaysian carrier, started flying this year and is expanding operations.

The plane's disappearance comes at a sensitive time for Indonesia's aviation authorities, as they strive to improve the country's safety reputation to match its status as one of the airline industry's fastest growing markets.