New | More than 1,000 armed police start patrols in Shanghai
Extra security introduced in the wake of the knife attacks in Kunming last month
More than 1,000 police officers started patrols in Shanghai carrying guns on Sunday, Xinhua reported.
The Ministry of Public Security said last month that more armed patrols would be introduced around the country in the wake of the knife attacks at Kunming railway station on March 1.
Twenty-nine people and four assailants were killed during the attacks that officials have blamed on Muslim separatists from Xinjiang. Most police officers on the mainland do not carry firearms.
As China has tight controls on firearms, most violent crime happens with knives, or homemade weapons.
The ministry said security would be stepped up in a number of mainland cities, including Changsha in Hunan province, Urumqi in Xinjiang and Lhasa in Tibet.
Xinhua reported last month that police would increase armed patrols, especially in busy areas like stations, airports, schools, hospitals and tourist attractions, in a drive to crack down on violent crime.