Three international students swapped their study books for uniforms after volunteering to be urban management officers during their summer vacation, Xiaoxiang Evening News reported Tuesday.

Qin Bo from the South Africa, Prince from Central Africa and Jawad from Afghanistan, volunteer as unban management officers in Hefei, Anhui province on July 14.

The new urban management recruits, known as chengguan in China, attracted puzzled looks from passers-by as they patrolled Anhui's capital of Hefei.

The volunteers, two African and one from Afghanistan, all study in the city and decided to offer their help to the local force, which is known for tackling street vendors, illegal taxis and parking issues.

One micro blogger posted about his surprise seeing the three with dark skin and white teeth speaking broken mandarin to a vendor about moving his stall away from a pedestrian street.

The Jianghuai Morning News reported a man became totally confused when he found three uniformed foreigners moving his motorcycle to a parking station, shouting "what are you doing? That's my bike".

Urban management officials told the paper they would like to invite more people from different backgrounds to be the city's guardians, although volunteers have no power to enforce the law.