A massive party organised by students using social networking sites brought university classes to a standstill on Thursday in the eastern Spanish city of Valencia.

The law and economics faculties at the city's university had to close their doors as drunken students began to run amok after more than a thousand people had gathered for an outdoor bring-a-bottle party at the campus.

The party was organised as a protest against the university's failure to put on a traditional student paella party this year.

"It will end when people tire of it, or when we get chucked out," organisers had promised on the Spanish answer to Facebook, a social networking site called Tuenti. "The aim is not to create a disturbance or to demonstrate against anyone, but to have a good time together."

Students carrying bottles, food, cooler bags and guitars packed out the campus, with the more drunken ones eventually disturbing classes.

Authorities said they had suspended classes to avoid incidents.

The students' union said it had nothing to do with the impromptu party, but blamed university authorities for the failure to organise the traditional annual student paella party.