LILLE (France) • Six passengers were seriously injured on Sunday in a spectacular accident in northern France when the top of a bus was shorn off while it was trying to pass under a low bridge.

Mr Frederic Fevre, the public prosecutor in Lille, said the six passengers were in grave condition.

The bus from Spain carrying 58 passengers had attempted to drive under a bridge prohibited to vehicles exceeding 2.6m in height.

Twenty-eight other passengers - mostly Spanish students aged 18 to 29 - were slightly injured when the accident occurred outside Lille.

"Most people were sleeping... (and) nobody understood what was happening," said a passenger who identified herself as Carlota. "All of a sudden, the roof of the tunnel was right there," she said, gesturing with her hand just above her head.

According to witnesses, the most severely injured passengers were at the rear of the bus, towards which the debris of the roof was thrust as the vehicle ploughed into the bridge.

Mr Fevre said the 59-year old driver of the bus had a good record, and assured the authorities he had followed instructions provided by his GPS. The authorities said testing for alcohol or drugs had come up negative.

Passengers who did not require hospitalisation were being put up in a local sports centre, waiting for repatriation to Spain.

"They're resting, we know stress is exhausting. They have called their families... Their return (home) is being organised," said Dr Francois Ducrocq, a psychiatrist working with an emergency aid team. AGENCE FRANCE-PRESSE