Satellite images not of MH370 crash: officials

China's civil aviation chief said on Thursday that there was no evidence that objects seen by satellite imagery floating in the South China Sea were connected to a missing Malaysia Airlines aircraft.

"Chinese satellites have found smoke and floating objects," Li Jiaxiang told reporters on the sidelines of China's annual meeting of parliament. "At present, we cannot confirm this is related to the missing aircraft."

The State Administration of Science, Technology and Industry for National Defence said on its website on Wednesday that a Chinese satellite had found three floating objects in the suspected area of the missing Malaysian plane.

The three objects were positioned at latitude 6.7 degrees north and longitude 105.63 degrees east, spread across an area with a radius of 20 kilometers. The image was captured on March 9.

China urged Malaysia on Wednesday to accelerate its search and rescue work for the missing plane and to strengthen coordination among search forces from different countries and regions.

"We won't give up as long as there is a shred of hope, and we urge Malaysia not to miss any clue and speed up search and rescue work," Foreign Ministry spokesman Qin Gang said.

Malaysia Airlines flight 370 was en route from Kuala Lumpur to Beijing early on Saturday with 239 people on board, including 154 Chinese nationals, when the Boeing 777-200 vanished from radar screens.

The multinational search entered its fifth day on Wednesday. Nearly 40 aircraft and 42 ships from 12 countries and regions, including China, Malaysia, Singapore and Vietnam, are scouring the waters around the jet's last known location, but no substantive clues have been found. China has sent eight ships and several aircraft to help with the search.

A Chinese work team sent to Kuala Lumpur headed by Guo Shaochun, deputy director of consular affairs at the Foreign Ministry, held a three-hour meeting on Wednesday with the Chinese passengers' family members who arrived in the Malaysian capital.

He Jianzhong, head of the China Maritime Search and Rescue Center, said Chinese vessels searching a suspected crash site are equipped with five helicopters and 12 professional divers.

Malaysia's ambassador to China, Iskandar Sarudin, met family members at the Lido Hotel in Beijing on Wednesday.

He said he will pass their demand to the Malaysian government that the country's military publicize information about its radar tracking of the aircraft before it vanished.

Malaysian authorities said earlier that air defense radar picked up traces of what might have been the plane turning back and flying until it reached the Strait of Malacca, a busy shipping lane west of the nation about 400 km from the plane's last known coordinates.

Malaysia's Acting Transport Minister, Dato Seri Hishammuddin Hussein, said on Wednesday the search has been expanded to two areas, Malacca and the South China Sea.

"We examined our military radar records for the new search area and discovered the possibility that MH370 had passed over the Straits of Malacca. We then dispatched ships and aircraft to search the new area," he said.

"Even if there is only a slight possibility, we decided it was imperative to extend the search to this area," he added.

The last radio transmission from the cockpit of the plane was "all right, good night", it emerged in Beijing on Wednesday.

One of the pilots said these words as the flight passed from Malaysian to Vietnamese airspace, according to Singapore's Straits Times newspaper, quoting Iskandar Sarudin, Malaysia's ambassador to China.

Malaysia's Department of Civil Aviation chief Azharuddin Abdul Rahman later confirmed to Agence France-Presse that those were the last words from the cockpit.

Authorities have not ruled out any possible cause for the plane's disappearance, including mechanical failure, pilot error, sabotage and terrorism.

Hou Liqiang, He Liu and agencies

contributed to this story.