The campaign, which will run until the end of August, will include household checks in Wangjing, Sanlitun and Wudaokou, areas of the city known for their high concentration of foreign residents, as well as on-the-spot street checks that will require foreigners to present valid identification, according to a spokesman from the Beijing Municipal Public Security Bureau.

　　Police have also opened a tip hotline and will tighten reviews of visa applications during the period, the spokesman said, adding that the tasks will be completed by officers capable of speaking foreign languages and trained in the handling of related matters.

　　Foreigners found to be violating relevant laws may face penalties ranging from fines or detention to deportation, according to the police.

　　"There are no special groups before the law. We will protect the legal rights of all people, including foreigners, who work and live in Beijing while punishing those who violate the law," the spokesman said.

　　Although not officially confirmed, the campaign is believed to be linked to the detention of a British man who allegedly attempted to sexually assault a Chinese woman on the side of a road in downtown Beijing on May 8.

　　According to data provided by the city government, Beijing is home to about 120,000 foreigners.

　　Gina Mitchelmore, a South African national working at an international kindergarten, said that for her and others who have followed protocol, the campaign may only affect them in a small way.

　　"Other than the possibility that we may be forced to carry our passports at all times, I don't foresee any direct effect on my own life here," Mitchelmore said.

　　According to Chinese law, it is illegal for foreigners to enter China without a valid visa issued by Chinese authorities or a legal passport, as well as through unofficial ports of entry.

　　It is also illegal for foreigners to live in China on expired visas or residence permits, as well as acquire paid jobs without a proper work visa.