Police in Xi'an, capital of Shaanxi province, are facing questions over dog catching, Huashang Daily reported on Tuesday.

A resident said in a micro blog on Monday that he saw four policemen catching pet dogs on a downtown street and the owners of the dogs had to pay for vaccinations and dog licenses to get them back.

Police said that Xi'an implemented dog-control measures 10 years ago in order to ensure safety for local residents, and the dog owners must get licenses.

"The cost for a vaccination and dog license is 500 yuan ($82) per dog and the dog owners should walk their dogs out on leashes during before 6 am and after 9 pm. The dogs without licenses will be caught and sent to a dog rescue center," said a police officer.