Beijing police officers will secretly search bars for drug traffickers and addicts as of Wednesday to root out such illegal activities ahead of the Olympic Games, local public security authority declared in a circular.

Bar owners and users will be investigated once they were found of being involved in drug-related activities during the two-month checkup, said Zhao Wenzhong, head of the drug-control department of Beijing Municipal Public Security Bureau.

The campaign is aimed at creating a drug-free environment for the grand sports event to be held here in August, he said.

The police officer explained that foreign- and youth-oriented bars are becoming a popular venue of drug smuggling and consumption.

Drug traffickers and users are gradually moving from large entertainment facilities and urban areas to small, rural ones to avoid intensified crackdown by the authority, Zhao added.

More than 20 Beijing-based entertainment resorts that were convicted of involvement in drug cases have been annulled since 2006, thanks to joint operations by various municipal authorities, according to Fu Zhenghua, deputy head of the bureau and also in charge of the city's drug control task.