SEPANG, Malaysia — Two Iranians known to have used stolen passports to board the Malaysia Airlines jet that disappeared on Saturday were unlikely to be linked to terrorist groups, international police authorities said, echoing an assessment by the Malaysian police that one of them was a 19-year-old who wanted to migrate to Germany.

The 19-year-old, Pouria Nourmohammadi Mehrdad, was using a stolen Austrian passport to travel to Germany, where he was to meet his mother, said Khalid Abu Bakar, the inspector general of the Malaysian police.

“We are in contact with his mother,” Mr. Khalid said at a news conference.

Interpol identified the second Iranian traveler as Seyed Mohammed Reza Delavar, 29,who used a stolen Italian passport, and released a photograph of the two men boarding Malaysia Airlines Flight 370 at the same time. Interpol confirmed the identity of the other Iranian, Mr. Mehrdad, but gave his age as 18. The source of the discrepancy was unclear.

Mr. Khalid said that the two men had arrived in Malaysia on the same day, Feb. 28.

At Interpol’s headquarters in Lyon, France, Ronald K. Noble, the agency’s secretary general, said the evidence emerging about the two Iranians suggested that they were not likely to be linked to any terrorist groups. “The more information we get, the more we are inclined to conclude it is not a terrorist incident,” Mr. Noble said.

He added that the two men had traveled to Kuala Lumpur on Iranian passports before using the stolen Italian and Austrian passports to board the flight.

Mr. Noble praised the Iranian authorities for their cooperation in confirming the identities of the two men. He said Tehran had also determined that neither of the men had a criminal record and that both had left Iran legally.

Image Khalid Abu Bakar, inspector general of the Malaysian police. Credit... Azhar Rahim/European Pressphoto Agency

The connection to Iran seemed to unsettle some authorities in Tehran, where a prominent lawmaker called the reports about the two Iranians “psychological warfare.”

“Americans recruit some people for such kinds of operations so they can throw the blame on other countries, especially Muslim countries,” said Hossein Naghavi Hosseini, the spokesman for Parliament’s foreign policy committee.

The Iranian Foreign Ministry struck a more cooperative note.

“We have received information on the possible presence of two Iranians” aboard the plane and “we are pursuing the issue,” said Marzieh Afkham, a spokeswoman. “We have informed our embassy in Malaysia that we are ready to receive further information about the issue from Malaysian officials. We have announced that we were ready for cooperation,” she said.

Mr. Khalid, the inspector general of the Malaysian police, said previous reports by Malaysian officials that five passengers had failed to board the flight were false. “Everybody that booked the flight boarded the plane,” he said.

Thousands of Iranians seeking to leave their home country wait in Asian countries with friendly visa regulations to make the second part of their migration to the West or Australia. Thailand, Malaysia and Indonesia are popular jumping-off points for middle-class Iranians who arrive on tourist visas and are then helped by local travel agents.

The police in the Thai resort town of Pattaya said that they had questioned an Iranian man who paid cash for the tickets of the two passengers who traveled on stolen passports.

The man they questioned, Hashem Saheb Gharani Golestani, 51, runs a frame shop in Pattaya and was a friend of another Iranian, a frequent customer of a local travel agency, who booked the tickets from abroad, the police said. Mr. Hashem was released after questioning, they said.

The stolen passports used to board the flight had been taken during the past two years in Phuket, another Thai beach resort. Both destinations attract budget tourists from Russia, China, Europe and the Middle East and have become centers of crime, particularly human trafficking and the counterfeiting of travel documents.