A China Eastern commuter plane crashed into a frozen lake seconds after take off in Inner Mongolia yesterday, killing 53 people on board and one on the ground, the airline and state media said.

"Witnesses said that the plane broke into flaming fragments, a house beside the park was damaged by the falling aircraft and several yachts nearby were scorched," Xinhua news agency said.

It quoted one witness as saying the plane was trailing black smoke and rocking violently when there was an explosion and the plane crashed and broke apart.

Xinhua said the plane smashed through a park ticket office and state television said one person on the ground was killed. It earlier said two. A local reporter said that when he arrived at the scene 30 minutes after the crash, a huge fire was visible on the surface of the lake.

Premier Wen Jiabao ordered all-out efforts to determine the crash's cause, state television reported in its national evening newscast. The Canadian-made Bombardier CRJ200, flown by two pilots, took off from the industrial city of Baotou, nearly 600 km west of Beijing, en route to eastern Shanghai, China Eastern Airlines Corp. Ltd. said on its web site.

The weather was clear, with the temperature around six to seven degrees Celsius when the plane, operated by a unit of China Eastern Yunnan Branch Co., crashed into the giant lake in Nanhai Park at 8.20 am, an airport official said.

The fire was put out at the lake and more than 400 people, including firefighters, police officers, park staff and a 20-member diving team from Baotou Iron and Steel, a major steel producer, joined the rescue work.

State television showed pictures of rescuers pulling debris from below the broken ice. The remains of 46 victims had been found but not the black box flight recorders, Xinhua said.

Police cordoned off the park, two km from the runway. China Eastern had grounded all of its CRJ200s until further notice, Xinhua said. It did not say how many the company flew, only that there were 29 in China flown by seven airlines.

A China Eastern spokesman said only that an investigation was under way. "High-standard hospitals in Baotou have made arrangements for receiving the remains of victims. And doctors and nurses are providing medical and related services for families of the dead," Xinhua said.

It said the passengers were all Chinese except for one Indonesian, and an investigation team had flown from Beijing to Baotou.

"No name list of the victims is available, yet local informed sources said that one of them was the chairman of a renowned company listed on the Shanghai Stock Exchange," Xinhua said.