Bejing ? College students in central China smashed offices and set fires in a riot sparked by administrative changes that made their diplomas less prestigious, students and school administrators said Monday.

Photos of the weekend riots posted on the Internet showed fires set in debris-strewn school courtyards and glass smashed in administrative offices, shops, cars and a bank.

Students said police with water cannons had moved onto the campus of Shengda Economics, Trade and Management College in Zhengzhou, the capital of Henan province. It was unclear whether there were any clashes.

There was no mention of the apparent riots in the country’s state-controlled media. Campus unrest is treated with extreme sensitivity in China, where 1989 student pro-democracy protests led to the bloody military crackdown in Tiananmen Square.

Zhengzhou police and local government and education officials said they had no details of the weekend protests or could not comment without permission from Communist Party officials.

However, an official with the school’s Communist Party committee confirmed the riots and said talks with students stalled Monday because their demands were unclear.

“The problem is the students aren’t being coherent. We don’t really know what they want,” the official said by telephone. He refused to give his name.