Over a dozen people were killed and several injured in a deadly accident in Spain when a bus collided with a car on one of the main highways in the country’s northeastern Catalonia province, according to an Associated Press (AP) report. The bus was carrying 50 people at the time of the accident, and rescue workers reportedly rushed to the spot.

Agencia EFE, a Spanish news agency, reported that at least 14 people were killed in the crash, citing a Spanish government agency. The report also said that the bus collided with a car on AP7 highway, which connects Spain to France along the Mediterranean coast near the Spanish municipality of Freginals between Valencia and Barcelona.

According to Spanish media reports, the highway was cordoned off and traffic diverted.

The AP report said that emergency workers were trying to rescue those in the bus, but a statement from the regional Catalonia government did not give an estimate of the casualties. The statement also reportedly said that the bus was carrying students back from a fireworks festival in Valencia.

The region’s Interior Minister Jordi Jané said in a press conference, according to the Guardian, that the victims were aged between 22 and 29 and added that “the majority are Erasmus students of various nationalities. We are trying to draw up a list of the victims.” He was also unable to confirm reports suggesting that all the students were from the University of Barcelona.

Jané also said, according to 324 Catalunya Informaciom, a local news network, that a preliminary investigation showed that human error could have caused the accident. The driver of the bus is currently in police custody.

“We still have to analyze the causes of the accident. Everything suggests that come from human factors,” Jané reportedly said.