SHANGHAI (AP) — A quarter of the police officers in Shanghai have begun carrying guns during routine patrols for the first time.

It is part of a China-wide boost in police firepower in response to a deadly mass knifing attack at a train station blamed on Xinjiang separatists.

Police in China generally haven’t carried firearms, and none of the officers patrolling the train station in the southwestern city of Kunming on March 1 was armed when at least five assailants began rapidly hacking victims, killing 29 and wounding 140.

In response, China plans to introduce armed police patrols throughout the country. The central city of Xi’an began armed patrols last Thursday. Shanghai says about 1,000 of its 4,000 police underwent special training and started carrying 9 mm pistols on Sunday.