Stolen passports

A combination photo shows two men whom police said were travelling on stolen passports onboard the missing Malaysia Airlines MH370 plane, taken before their departure at Kuala Lumpur International Airport in this March 11, 2014 handout courtesy of the Malaysian Police. Malaysian police named one as Pouria Nour Mohammad Mehrdad (L), 18, and said he was probably migrating to Germany. Interpol identified the other as Delavar Seyed Mohammadreza, 29. [Photo by Peng Yining/chinadaily.com.cn]

The fact that at least two passengers on board had used stolen passports has raised suspicions of foul play. But Southeast Asia is known as a hub for false documents that are also used by smugglers, illegal migrants and asylum seekers.

Interpol Secretary General Ronald Noble named the two men as Iranians aged 18 and 29, who had entered Malaysia using their real passports before using the stolen European documents to board the Beijing-bound flight.

"The more information we get, the more we are inclined to conclude it is not a terrorist incident," Noble said.

In Washington, the director of the Central Intelligence Agency said intelligence officials could not rule out terrorism as a factor. "You cannot discount any theory," CIA Director John Brennan said.

Malaysian police chief Khalid said the younger man, who he said was 19, appeared to be an illegal immigrant. His mother was waiting for him in Frankfurt and had been in contact with authorities, he said.

"We believe he is not likely to be a member of any terrorist group, and we believe he was trying to migrate to Germany," Khalid said.

Asked if that meant he ruled out a hijack, Khalid said: "(We are giving) same weightage to all (possibilities) until we complete our investigations."

Both men entered Malaysia on Feb 28, at least one from Phuket, in Thailand, eight days before boarding the flight to Beijing, Malaysian immigration chief Aloyah Mamat told the news conference. Both held onward reservations to Western Europe.

Police in Thailand, where the Italian and Austrian passports were stolen and the tickets used by the two men were booked, said they did not think they were linked to the disappearance of the plane.

"We haven't ruled it out, but the weight of evidence we're getting swings against the idea that these men are or were involved in terrorism," Supachai Puikaewcome, chief of police in the Thai resort city of Pattaya, told Reuters.

About two-thirds of the 227 passengers and 12 crew now presumed to have died aboard the plane were Chinese. Other nationalities included 38 Malaysians, seven Indonesians, six Australians, five Indians, four French and three Americans.

China has deployed 10 satellites using high-resolution earth imaging capabilities, visible light imaging and other technologies to "support and assist in the search and rescue operations", the People's Liberation Army Daily said.

US government officials from the National Transportation Safety Board and the Federal Aviation Administration have arrived in the region to provide "any necessary assistance" with the investigation, White House spokesman Jay Carney said in Washington.

The Boeing 777 has one of the best safety records of any commercial aircraft in service. Its only previous fatal crash came on July 6 last year when Asiana Airlines Flight 214 struck a seawall on landing in San Francisco, killing three people.

US planemaker Boeing has declined to comment beyond a brief statement saying it was monitoring the situation.