The victims of Sunday's crash, all aged between 19 and 25, also included a Romanian, a Frenchwoman, an Austrian and a student from Uzbekistan, Jordi Jane, who heads up interior matters for Catalonia, said on the radio.
"Some of them were not wearing seat belts," Jane said.
The students from 19 countries - the UK, Ireland, Peru, Bulgaria, Poland, Palestine, Japan, Ukraine, the Czech Republic, New Zealand, Hungary, Sweden, Norway and Switzerland - were all enrolled at universities in Barcelona, many as part of the Erasmus European exchange programme.
As well as the dead, 24 people were injured, with seven in a serious condition.
Identification of the victims has proven difficult as many were not sitting in their assigned seats on the return journey.
"Erasmus Student Network Spain would like to request the public for discretion in respect for the families and friends, to whom we send our deepest condoloences," the Erasmus student organization said.
"In addition, we would like to thank all the volunteers and emergency services for their diligent work in these sad circumstances."
Dangerous stretch of road
The driver lost control of the coach at around 6 am on Sunday, hitting a railing before swerving into the wrong side of the highway and crashing into an oncoming car.
The accident occurred near the 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.
Freginals mayor Jose Roncero Pallares said that that stretch of highway had a history of accidents.
"I don't know why, that highway looks fine and it's a straight line," he told AFP.
"It rained a lot that night and maybe that played a role."
No drugs or alcohol
The driver, who was questioned by police Sunday, is in intensive care being treated for chest injuries, Jane said. He was due to appear before a judge on Monday, but the hearing has been postponed, a legal source told AFP.
Media reports on Monday suggested that the driver may have been asleep at the wheel.
He was an employee with seventeen 17 years' experience and no reported accidents.
"It appears an undetermined human error and not a mechanical failure was to blame," Spain's Interior Minister Jorge Fernandez Diaz said.
"The driver has tested negative for alcohol and drugs so those factors are ruled out."
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