Four people have been given public security punishments for spreading rumors of a group of HIV/AIDS carriers attempting to deliberately transmit their virus by contaminating food.

The four, who are all from northwest China's Xinjiang Uygur autonomous region, have apologized for spreading the rumor via mobile phones, microblogs, QQ and other online forums, said a spokesman with the public security department of the region on Tuesday.

The spokesman refused to disclose the nature of the punishment or the full names of the four people.

According to the information he disclosed, the four people include one surnamed Mu from Shihezi city, one surnamed Liu from Urumqi, one surnamed Zhang from the Kazak autonomous prefecture of Ili, and a fourth surnamed Gan from the Mongolian autonomous prefecture of Bayingolin.

They spread the rumors of an "AIDS blood attack" between November 11 and 16, said a post released by the public security authority on its official microblog.

The rumors claimed that a large group of HIV carriers from Xinjiang had swarmed into major cities across China and contaminated restaurant food with their blood, infecting one diner. The spokesman added that, as of Tuesday, no such case or victim had been found.