Thirteen students were killed and dozens more injured in Spain Sunday when the driver of their coach lost control and crashed into an oncoming car as they returned from a festival.

The bus was carrying students aged between 20 and 32 -- many on a European exchange programme in the northeastern region of Catalonia -- from some 20 countries including Britain, the Netherlands, Ukraine, Switzerland, Norway and Sweden but also Japan and Peru.

Six of the more than 30 injured were in a critical condition in hospital.

All the fatalities were female, according to Jordi Jane, who heads up interior matters for Catalonia, but authorities have yet to announce their nationalities.

A spokeswoman for the Italian foreign ministry, however, said there may be Italian nationals among the victims.

"We fear there may be seven Italians among the dead. We are not sure as identification procedures are still ongoing," she said.

It was unclear whether Spanish nationals were among the passengers.

The accident occurred just before 6 am (0500 GMT) near the small town of Freginals, about 150 kilometres (95 miles) south of Barcelona as the students were returning from the Fallas festival in eastern Valencia known for the burning of giant statues.

- 'Swerved' -

The bus driver "hit the railing on the right and swerved to the left so violently that the bus veered onto the other side of the highway," said Jane.

The bus then hit a car coming in the opposite direction, injuring two people inside, he added.

Spain's Interior Minister Jorge Fernandez Diaz, who went to the scene, said it was still not clear why the bus driver hit the railing in the first place, adding however that the accident was likely due to a "human factor".

An AFP photographer at the scene several hours after the crash said many fire engines were there, as were three hearses and a heavy-lift crane.

The car's front was smashed in, and the bus was lying on its side after the accident.

It was eventually lifted onto a truck and driven away -- its windscreen smashed and the back part of its roof caved in.

Jose Roncero Pallares, the mayor of Freginals, said the accidents that had hit that stretch of the motorway over the past years had always taken place in the area where the crash happened.

"I don't know why, the highway looks fine and it's a straight line," he told AFP.

"It rained a lot that night and maybe that played a role."

Catalonia's high court said in a statement that an initial probe revealed "the bus driver tested negative for drugs and alcohol".

- Minutes of silence -

The accident is one of the deadliest in Spain in recent years.

In November 2014, a bus carrying pilgrims fell into a ravine in the southeast of the country, leaving 14 dead and another 41 injured.

Spain's Prime Minister Mariano Rajoy tweeted his concern on Sunday.

"My condolences to the families of the victims and I wish rapid recovery to the injured," he wrote.

Catalonia's newly-elected regional president Carles Puigdemont, meanwhile, visited the area after cancelling a planned trip to Paris.

Joining in mourning for the tragedy, players for Barcelona and Villarreal -- which is only around 100 kilometres (62 miles) from the crash site -- observed a moment of silence before kick-off, as will those from the Real Madrid and Sevilla later Sunday.

Source :AFP