Shenzhen has evicted more than 80,000 people out of the city in a special crackdown aimed at improving security ahead of the Universiade 2011 sports event, Guangdong-based New Express Daily reported.

The measures triggered controversies among local residents and Internet users, with some arguing it is necessary to strengthen security, while others saying it is discrimination.

Police in Shenzhen announced at a press conference Sunday that they had evicted people with "high risks to public security" last week.

"The difficulty of security work for the Shenzhen Universiade lies in the management of those floating people, especially those who pose high risks to the public security," said Shen Shaobao, spokesman and vice director of the Shenzhen Public Security Bureau.

Those considered "high risks" include people who sleep during the day and go out at nights without stable jobs, Shen explained, and those who use fake identity cards to rent apartments or those who live on illegal incomes.

Mental patients who have committed offenses or pose a potential risk to people were also targets, he confirmed.

"Over 80,000 people who pose high risks to public security have left the city out of fear, but it's not over," Shen said.

Shen did not specify how many officers had been involved in evicting these people and local police bureaus declined interview requests made by the Global Times.

Shenzhen, the economic hub that evolved from a fishing village in the early 1990s, is to host the international sport event for university athletes during August.

The city launched a 100-day security overhaul, inspecting thousands of rented houses, entertainment venues as well as Internet cafés early this year.

The clampdown had led to the arrest of more than 6,000 suspects, with nearly 2,000 people detained and some 800 drug users sent to rehab, Shenzhen Economic Daily reported Monday.

The crackdown has drawn heated debate with some Internet users arguing that the definition of "high risks to public security" is too ambiguous.

"I feel like I have been pushed away and discriminated against," Xu Yihui, a Zhejiang Province native who works in Shenzhen, told the Global Times.

However, some Internet users welcomed the crackdown.

"There are many illegal Internet cafés," an Internet user Matongzhuanjia said. "I suspect drug trafficking and prostitution are common there."

Another Web user Jipingdingye hoped the crackdown by the police will last longer.

It is normal for police to step up efforts before such an important event and also understandable that some people chose to leave facing tightened security, said Chen Tianben, an associate professor at the Chinese People's Public Security University.