Seven Italians and two Germans were among the 13 female students killed in a bus crash in north-eastern Spain, Catalan Interior Minister Jordi Jane said Monday.
Jane also told Catalunya Radio there was one victim each from Romania, France, Austria and Uzbekistan and that the more than 40 injured on Sunday included two other Germans. The dead were between 19 and 25 years old.
Germany's Foreign Ministry declined to confirm the number of German casualties, saying only that it "cannot rule out" the fact that some of its nationals were among those killed.
Italian Prime Minister Matteo Renzi expressed his sadness over Twitter.
"Heartbroken over the Italian victims and other young lives destroyed in the accident in Spain," he wrote.
Spain's El Pais newspaper reported that initial investigations suggest the driver may have fallen asleep.
Jane said the driver was suspected of causing the crash, and Spanish state radio RNE reported he had been due to go before a judge on Monday. However, a hearing has been put back because he is still in hospital with injuries to his lung.
The driver tested negative for drugs and alcohol, judicial authorities in Barcelona said.
The packed bus overturned and crashed into another vehicle on a highway near the port city of Tarragona on Sunday.
There were 61 people on the bus, which was transporting international students participating in the EU's student exchange programme known as Erasmus back to Barcelona from a folk festival in Valencia.
Among the dead and injured were people from 19 different countries, the Catalan rescue services said.
In Catalonia, the regional government has ordered two days of official mourning. Flags in the region flew at half-mast. Spain's King Felipe VI also held a minute's silence for the victims.