BEIJING, March 11 (Xinhua) -- One of two passengers using stolen passports on board a missing Malaysian jetliner has been identified as an Iranian with no link to terrorism, Malaysian police said Tuesday as a massive multinational search for the plane entered its fourth day.
Khalid Abu Bakar, Malaysia's national police chief, told a press conference in Kuala Lumpur the 19-year-old Iranian boarded the plane using a stolen Austrian passport.
"We believe that he is not likely to be a member of any terrorist group, and we believe he is trying to migrate to Germany," Khalid said.
The young man's mother was waiting for him in Frankfurt, the official said, adding, when he didn't arrive, she contacted Malaysian authorities.
However, Khalid did not rule out terrorism as a possible cause of the disappearance of the Malaysia Airlines Flight MH370.
"I would not say (terrorism is) less likely. Same weightage to all until we finish our investigations," he said.
He said the identity of the other man using a stolen passport was still under investigation. It has separately been revealed that man is also an Iranian passport holder.
Meanwhile, Interpol Secretary General Ronald Noble said the plane's disappearance was not likely to have been caused by a terrorist attack.
"The more information we get, the more we are inclined to conclude it was not a terrorist incident," Noble told reporters at the international police agency's headquarters in Lyon.
He said the two Iranian passport holders, who started their trip in the Qatari capital of Doha, may have been part of a people-smuggling operation.
"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, adding neither of the Iranian passports were reported stolen or lost.
In Tehran, Iranian Foreign Ministry spokeswoman Marzieh Afkham said her country would follow up the case of the two Iranians.
"We have also heard about two Iranians on the missing Malaysian flight and we are following up the issue," she said in her weekly press briefing.
"We have announced our readiness to cooperate (with officials) through our embassy in Malaysia," Afkham said.
Also on Tuesday, Do Minh Tuan, deputy commander of the Vietnamese Air Force, told a media conference Vietnam had widened the search east and west of the Gulf of Thailand.
He said Vietnamese authorities had not only called its navy and air force into action, but also enlisted local fishermen in the effort, asking them to report any suspicious objects they sighted.
Asked when the search operation would come to an end, he said the search effort would continue and probably on a bigger scale, and that no time limit would be set.
Vietnam had sent 10 sorties of aircraft for the operation and planned to ask China to send two more aircraft as reinforcements, Tuan said.
Earlier in the day, a second Chinese naval vessel joined the massive international hunt for the missing plane, but has so far found no clues.
Upon its arrival Tuesday morning, the Jinggangshan teamed with the Mianyang, which arrived Monday, and promptly started search operations.
The two naval vessels are on a 24-hour search pattern with all their monitoring systems activated, including radar, infra-red and optoelectronic searching devices. Two helicopters aboard the Jinggangshan are also involved in the air search.
"The search involves air, sea and underwater forces, and it can increase our chances of finding the missing plane," said Wang Yongxiang, deputy chief of staff of the South China Sea Fleet.
"We will carry out immediate rescue or salvage operations once we spot persons in distress, suspicious floating objects or underwater targets," Wang said.
According to the Chinese navy, another two warships are also expected to reach the area soon, and a supply ship has been ordered to prepare to move into the Gulf of Thailand to replenish the search vessels.
Dozens of ships and planes from around 10 countries are scouring the waters around Flight MH 370's last known location, but no solid clues have been found so far.
The Boeing 777 aircraft suddenly vanished from radar early Saturday morning while carrying 227 passengers and 12 crew members from Kuala Lumpur to Beijing. Among the passengers, 154 are Chinese.
Chinese President Xi Jinping has ordered an all-out search and rescue effort. Several Chinese civilian ships have already been sent to assist the mission.