BEIJING - Chinese forces on Friday continued the searching mission and expanded searching area for the missing Malaysia Airlines jet that carried 154 Chinese passengers, but the whereabout of the flight remained a mystery.

The search will be expanded to the east and west, with intensive search in the east region and enhanced efforts in the southeast from Saturday, according to the China Maritime Search and Rescue Center.

China will also augment logistics support and arrange search rotations of different vessels, said He Jianzhong, director of the center.

Eight Chinese vessels had searched 70,078 square kilometers of the sea's surface as of 6 p.m. Friday, covering 68,463 square kilometers of waters underneath. No confirmed debris has been found yet.

The Chinese patrol ship Haixun 31 left the waters around the Gulf of Thailand for the strait at 6 p.m. Friday and headed for the Strait of Malacca to search for the missing flight, after searching over 60,000 square kilometers for more than 120 hours without finding any sign of the aircraft, according to the center.

Meanwhile, forces will continue to mobilize Chinese merchant ships from COSCO, China Shipping, Sinotrans and other companies, to search in designated areas in the Strait of Malacca, said He Jianzhong, the center chief who is also vice minister of transport.

On Friday morning, experts and officials from China's multiple government departments as well as the navy also held a counsel meeting during which they analyzed new information and discussed plans to improve search and rescue work.

Malaysia Airlines flight MH370, a Boeing 777-200ER, suddenly went missing on its way to Beijing last Saturday morning shortly after taking off from Kuala Lumpur. The plane was carrying 12 crew members and 227 passengers.

University of Science and Technology of China announced on Friday that researchers have detected a "seafloor event" near the waters between Malaysia and Vietnam, an area suspected to be linked with the missing flight.

The event occurred at about 2:55 a.m. local time on Saturday, about one and a half hours after the plane's last definitive sighting on civilian radar, according to a research group on seismology and physics of the earth's interior under the university.

The area, 116 km northeast from where the last contact with the Boeing plane was recorded, used to be a non-seismic region. And the location of the event was identified based on records of two seismographs located in Malaysia, according to the group.

"The seafloor event could have been caused by the plane possibly plunging into the sea," the research group said.

If the data is proved to be linked to the missing flight, "the strength of the earthquake wave indicates the plunge was catastrophic," according to the research group.

On the same day, Foreign Ministry spokesman Hong Lei again urged Malaysia to take the lead in coordinating international search efforts for missing flight.

"We hope Malaysia can enhance collection and analysis of information and help all forces search more efficiently," Hong said at a regular news briefing.

Hong said the Malaysian side informed us of latest information regarding the missing flight on Thursday through diplomatic channels and has made tremendous search and rescue efforts in a candid manner.

While the whereabouts of the plane remain unknown, passengers' relatives and the Chinese public are very worried, he said.

China also urged Malaysia to give information on the search in the Strait of Malacca and the Andaman Sea in a timely manner, he added.

And he said China appreciates India's participation in the search in the Andaman Sea.

Rumors have been spread from multiple sources since search and rescue operations by multiple nations have failed to find the trace of the plane as yet.

Guo Shaochun, who heads China's joint working group in charge of the missing Malaysia Airlines flight incident, called for rationality over the issue of the missing jetliner on Friday.

Guo told the media in Kuala Lumpur that they had noticed there were some reports and speculations that the missing flight MH370 had been hijacked or under terrorist attack. "Before the investigation result is given out by professional agencies of related countries, we will not comment on this," said Guo, who is the deputy head of the Department of Consular Affairs with the Chinese Foreign Ministry.

Guo meanwhile urged people to be rational and not believe in or spread rumors which may affect or disturb related investigations. "Whenever there is any progress, we will release it in time," he said.

DEEPENED MYSTERY

More than 80 ships and planes from 13 countries are now combing the waters on both sides of the Malaysian peninsula to locate the missing plane.

Malaysia on Friday confirmed that search areas for missing flight have been widened to cover the Indian Ocean.

"Our priority remains finding the plane," said Malaysian acting Transport Minister Hishammuddin Hussein at a press conference.

But he made no comment on U.S. reports that the aircraft sent signals to a satellite for four hours after it went missing. He said the international team are currently working on verifying detailed information, but "we have nothing to confirm at this moment."

He added that as is the standard procedure that the investigation team will not publicly release information until it has been properly verified and corroborated with the relevant authorities.

Meanwhile, Malaysia Airlines made a statement which says that there's " nothing further to add to the information" they have already provided despite various on-going media speculations.

The airline reiterated it "will continue to give full support in cooperating with the search and rescue mission which is coordinated by the Department of Civil Aviation Malaysia (DCA) under the purview of the Ministry of Transport, Malaysia."

The airline also said that conflicting information about flight MH370 results from looking for the truth.

Families of the missing have reported that their loved ones' phones were still ringing days after the plane disappeared, causing widespread speculation.

"There is one phone still ringing now. We passed the number to the telecommunications company but details are confidential. If I tell family members that it is not real, I am taking away their hope," Hugh Dunleavy, commercial director of Malaysia Airlines said during a interview with Xinhua.

"Normally air traffic control receives data from the aircraft, but this time they did not. Not one single signal was received, which seems like a big mystery to me," he added.

Malaysian Prime Minister Najib Razak prayed for the passengers and crew on the missing Malaysia Airlines flight MH370 in a mosque near Kuala, without making any comment on the futile search efforts for the missing plane involving aircraft and vessels from a dozen countries.