A young man dressed in Halloween costume for Halloween takes part in a flash mob to celebrate Halloween at a metro station in Nanjing city, East China's Jiangsu province, on October 31, 2014.[Photo/IC]

BEIJING - Passengers on Beijing subway should avoid wearing strange outfits that might jeopardize public safety, warned police in China's capital on Wednesday.

According to Liang Jianwei, vice head of the Beijing municipal traffic administration corps, costumes and masks are likely to attract the attention of other passengers. When a lot of people stop to watch, the risk of stampedes increases.

He also suggested that passengers avoid forming flash mobs in the underground.

"Although such behavior is not banned by law, passengers should not be too willful," said Liang. Police will warn against problematic behavior when they come across it, he added.

"Beijing subway carries more than 10 million passengers each day," added Liang. "Everyone should be aware of safety."

Law enforcement team s began patrolling in Beijing subway stations and trains on May 1. During the past fortnight, they have encountered 83 cases of improper behavior, including hawking, begging and distributing advertising flyers.