By Johnny Cotton
LYON, France, March 11 (Reuters) - The international police agency Interpol does not believe the disappearance of a Malaysia Airlines jet was the result of a terrorist attack, its head said on Tuesday.
Interpol Secretary General Ronald Noble also suggested that two men who boarded using stolen passports and had aroused suspicion may have been smuggled by traffickers.
The plane, with 239 people on board, has been missing for four days and a search involving crews from 10 countries widened on Tuesday to a larger swathe of the Gulf of Thailand and South China Sea.
"The more information we get, the more we are inclined to conclude it is not a terrorist incident," Noble told a news conference.
Two Iranian passport holders aged 18 and 29, who started their trip in Doha, had swapped their passports in Kuala Lumpur and used stolen Italian and Austrian passports to board the airliner, he told reporters at Interpol's headquarters in Lyon.
"We know that once these individuals arrived in Kuala Lumpur on the 28th of February they boarded Flight 370 using different identities, a stolen Austrian and a stolen Italian passport," he said.
Later on Tuesday, Interpol said in a statement that the identity of the two Iranian nationals had been confirmed by Iranian authorities as Seyed Mohammed Reza Delavar, 29, and Pouria Nourmohammadi, 18.
Interpol is working with member states to follow all leads including "terrorism, organised crime, illegal movement of people, whether in the form of human trafficking or smuggling", Noble said.
Making public the names of the two individuals listed on the Iranian passports might compel family and friends to offer tips that could allow authorities to exclude terrorism theories.
"By doing this, eventually, with more and more evidence, we'll able to exclude they were involved in conduct that might have involved the plane to disappear, and focus on eliminating the human trafficking ring that allowed them to travel."