BEIJING, March 8 -- China is worried over the missing Malaysia Airlines flight scheduled to arrive in Beijing on Saturday morning, with search and rescue operations under way.

Contact has been lost with a flight from Kuala Lumpur, Malaysia, to Beijing, China's Civil Aviation Administration (CAAC) confirmed on Saturday.

The Boeing 777-200 aircraft left the Malaysian capital at 12:41 a.m. Beijing time on Saturday, and was expected to land in Beijing at 6:30 a.m. the same day, according to Malaysia Airlines.

The CAAC confirmed the flight number was MH370, which was carrying 239 people, including 12 crew members and more than 150 Chinese passengers. So far, the flight hasn't contacted the Chinese air traffic management department or entered China's air traffic control area.

Contact with the flight was lost along with its radar signal at 1:20 a.m. Beijing time on Saturday when it was flying over the Ho Chi Minh air traffic control area in Vietnam.

Malaysia Airlines said on its website that the company is trying to locate the flight with emergency rescue teams.

Chinese President Xi Jinping on Saturday ordered the Ministry of Foreign Affairs as well as Chinese embassies and consulates to strengthen contact with departments of relevant countries and pay close attention to the search and rescue work for the missing plane.

All-out efforts must be made for any emergency treatment necessary in the aftermath of the incident, Xi said in his instruction.

The Ministry of Transportation and the CAAC must launch emergency measures immediately and enhance security checks to ensure the "absolute safety" of China's civil aviation operation, according to the president.

Premier Li Keqiang also instructed the government to intensify communication and contact with civil aviation agencies of Malaysia, urging them to intensify the search effort.

He also called for details of the Chinese passengers aboard the plane to be verified as soon as possible.

Relevant departments should cooperate with foreign parties to prepare for emergency rescue and liaise with passengers' families in a timely and appropriate manner, Li said.

Yang Chuantang, Chinese minister of transport, announced the launch of the highest-degree emergency response mechanism.

The ministry is closely observing the incident and actively coordinating with domestic authorities as well as maritime rescue authorities and civil aviation administrations in Malaysia and Vietnam.

Yang also put the professional rescue forces in the South China Sea on standby.

The CAAC demanded its air traffic management office keep in touch with its Malaysian counterpart, and ordered Beijing Capital International Airport (BCIA) to comfort relatives and friends waiting anxiously for the arrival of the missing flight.

Malaysian Chuang Ken Fei had been waiting for his two friends in Terminal 3 of BCIA when he said, "Staff at the airport told me the flight did not take off, but I can see from my mobile application that the aircraft was in the air."

BCIA has formed an emergency group to deal with the incident.

Foreign Minister Wang Yi said on Saturday that China is very worried over the missing flight. "The news is very disturbing. We hope everyone on the plane is safe," said Wang.

Yin Zhuo, a member of the National Committee of the Chinese People's Political Consultative Conference, said that China must improve its search and rescue capacity on the sea, as it is still not strong enough.

A communication manager for Boeing China told a Xinhua reporter, "We are closely monitoring reports from the MH370 flight of Malaysia Airlines. Our thoughts are with everyone on the plane."

The flight was a code share with China Southern Airlines. A spokesman for China Southern Airlines said they are investigating whether any of the company's passengers were on board.

The plane took its first flight on May 14, 2002 and Malaysia Airlines took possession of the aircraft on May 31 of the same year.

Malaysia Airlines operates in Southeast Asia, East Asia, South Asia, the Middle East and on the route between Europe and Australia. It has 15 Boeing 777-200 models in its fleet.

On July 6, 2013, another Boeing 777-200 operated by Asiana Airlines, a carrier based in the Republic of Korea, crashed on the route between Seoul Incheon International Airport and San Francisco International Airport while attempting to land. Three Chinese female students were killed and more than 180 people were injured.