Hundreds of Chinese students protested in the streets of Xian over allegedly sexually explicit behavior at a party held by Japanese university students, the official Xinhua News Agency reported Friday.

The Japanese Embassy in Beijing said two Japanese students were slightly injured when they were attacked by angry Chinese students at the foreign students' dormitory during the incident.

According to a spokesman for the education agency of Shanxi Province, three Japanese students and a Japanese professor at Northwest China University wore red bras and hung false genitals made from paper from their waists as part of a performance at a cultural festival sponsored by the university's foreign language school held Wednesday night, Xinhua said.

They allegedly danced while tossing paper scraps from the bras, but the audience became outraged and had them stop.

From noon Thursday, Chinese students protested on the campus, gathering in front of the exchange student dormitory claiming "humiliation" and demanding an apology, Xinhua said.

Then, from 6:40 to 10 p.m., they marched on a downtown plaza carrying petitions for the local government demanding the Japanese involved apologize publicly.

In Tokyo on Friday, Foreign Minister Yoriko Kawaguchi said she was aware that there had been a riot of sorts in Xian, and that officials from the Japanese Embassy in Beijing had been dispatched to the university to look into the incident.

She added that as of early Friday, the school had transferred all exchange students, including Japanese, to a hotel to ensure their safety.

The protest comes only a few weeks after many Chinese flew in a rage over reports that revelers on a Japanese company trip to China hired hundreds of Chinese prostitutes and behaved "improperly" at a southern China hotel.