KUALA LUMPUR, Malaysia » A Malaysia Airlines Boeing 777-200 aircraft carrying 239 people lost contact over the South China Sea early Saturday morning on a flight from Kuala Lumpur to Beijing, and international aviation authorities still have not located the jetliner several hours later.

The plane lost communication two hours into the flight in Vietnam’s airspace at 8:20 a.m. Friday Hawaii time, China’s state news agency said. The radar signal also was lost, Xinhua reported.

Fuad Sharuji, Malaysian Airlines’ vice president of operations control, told CNN that the plane was flying at an altitude of 35,000 feet and that the pilots reported no problem with the aircraft. He said that the aircraft’s last communication was over the South China Sea between Malaysia and Vietnam.

Flight MH370 departed Kuala Lumpur at 6:41 a.m. Friday Hawaii time and was expected to land in Beijing at 12:30 p.m. Friday Hawaii time, Malaysia Airlines said.

The plane was carrying 227 passengers, including two infants, and 12 crew members, the airline said. Passengers were from at least 12 countries, including 152 from China, seven Australians and four Americans.

The airline said it was working with authorities who activated their search and rescue teams to locate the aircraft. The route would take the aircraft from Malaysia across to Vietnam and China.

"Our team is currently calling the next-of-kin of passengers and crew. Focus of the airline is to work with the emergency responders and authorities and mobilize its full support," Malaysia Airlines CEO Ahmad Jauhari Yahya said in a statement.

"Our thoughts and prayers are with all affected passengers and crew and their family members," he added.

All countries in the possible flight path of the missing aircraft were performing a "communications and radio search", said John Andrews, deputy chief of the Philippines civil aviation agency.

At Beijing’s airport, Zhai Le was waiting for her friends, a couple, who were on their way back to the Chinese capital on the flight. She said she was very concerned because she hadn’t been able to reach them.

Airport authorites posted a written notice asking relatives and friends of passengers to gather to a hotel about 9 miles from the airport to wait for further information, and provided a shuttle bus service.

Another woman wept aboard the shuttle bus while talking by mobile phone, " They want us to go to the hotel. It cannot be good!"

Malaysia Airlines last fatal incident was in 1995, when one its planes crashed near the Malaysian city of Tawau, killing 34 people.

Malaysia Airlines has 15 Boeing 777-200 jets in its fleet of about 100 planes. The state-owned carrier last month reported its fourth straight quarterly loss.

The 777 had not had a fatal crash in its 20 year history until the Asiana crash in San Francisco in July 2013. All 16 crew members survived, but three of the 291 passengers, all teenage girls from China, were killed.

Associated Press writers Chris Brummitt in Hanoi, Vietnam, Didi Tang and video producer Aritz Parra in Beijing, China, contributed to this report.