Chinese police patrol the streets in Italy, to protect Chinese tourists .
http://www.cnn.com/2016/05/03/travel/chinese-police-italy-rome-milan-tourists/
First of all, the Chinese policeman did not wear side arms in the photos, and they were paired with Italian police personnel, so this might just be a service type instead of really protecting the Chinese citizens.
We had loads of tourists from this country to Europe for decades, never had this kind of service.