Shanghai set a new rule aimed at collecting and controlling stray dogs. If nobody claims ownership within 30 days, the dogs will be put to sleep, the Guangzhou Daily reported Wednesday.

Police said that every year from 2006, there were more than 100,000 cases of dogs attacking residents, and the number in 2009 reached almost 140,000.

The rule became a hot topic and some people wrote in their micro blogs to express support for the rule because they believed stray dogs were causing the spread of rabies. And some people said dogs that do not have rabies should not be put down.