A French high-speed TGV train travelling from the eastern city of Strasbourg to Paris derailed on Thursday after an embankment collapsed into the tracks, seriously injuring the driver and hurting 20 others.

The driver, whose injury was not specified, was evacuated by helicopter following the accident near Ingenheim, around 30 kilometres (20 miles) northwest of Strasbourg.

The train was still intact but the locomotive was leaning on its side and four other wagons were also off the tracks, according to the state rail operator SNCF and AFP journalists at the scene.

"Despite going off the tracks, the TGV remained upright," the operator said in a Twitter post that included a picture of what it called "a major landslide."

The crew chief on the train also suffered a back injury and one passenger was hurt in the face, the SNCF said. A total of 21 people were injured, according to local authorities.

"The necessary security mechanisms to ensure the safety of the 300 passengers onboard functioned perfectly," it added. 

Local authorities for their part put the total number of passengers at 348.

Nearly 100 rescue workers and dozens of fire trucks were at the scene of the accident, which occurred around 20 minutes after the train left Strasbourg at 7:19 am (0619 GMT).

'Like in a washing machine'

An SNCF spokesman said the train was travelling at 270 km/h (170 mph) when it was derailed by an embankment collapse that damaged the tracks near Saverne in the Alsace region bordering Germany.

"But the driver was able to activate the emergency brake," another spokesman told AFP.

Passenger Alexandre Sergeant told BFM television by telephone: "All of a sudden we felt an impact, and then the train was on the gravel, it kept rolling for a while and then started to lean on its side." 

"We're in the third wagon, all the windows are broken, and our wagon is off the tracks," Sergeant said.

Many passengers were shaken by the accident, with some saying their backs had been hurt, but "there wasn't any wave of panic," he said.

Another passenger, who gave his name as Philippe, told the Top Music local radio station that "It felt like we were in a washing machine."

"Rocks were flying everywhere and the windows all shattered," he said. "We were all in a bit of shock."

The SNCF said other trains were still operating between Strasbourg and Paris, bypassing the site of the accident on an alternative route.

The mayor of Ingenheim has opened a public event centre to take in passengers, the website of the Dernieres Nouvelles d'Alsace newspaper.