Guangzhou must improve its management of the growing number of illegal immigrants there, a new report says.

The report - published by the Guangzhou Developmental Academy with Guangzhou University - says Guangzhou has a transient foreign population of more than 1.92 million, the highest of any Chinese city. Another 28,000-plus expatriates stay in the Guangdong provincial capital for more than six months.

The report said that half of the temporary-stay foreigners come from Africa, and that Guangzhou has the largest settlement of Africans in Asia due to "its good climate, geographical position, business environment and tolerance".

The report said problems involving foreigners who illegally immigrate, overstay and are employed without work permits are serious in all of Guangdong.

In 2007, police investigated more than 7,000 foreigners on accusations of being in Guangdong illegally. Over just a year, the figure almost doubled to more than 13,000 in 2008, including 210 illegal immigrants allegedly involved in 26 types of crimes.

The report suggested the government should adopt measures used by Germany and other Western countries to handle those countries' own growing number of foreigners who illegally enter, overstay, work without permits or conduct business without a license.

Suggested measures include establishing special refugee camps, detention houses and special organizations for illegal immigrants.

Zhang Yiri, an associate professor at Guangzhou City Polytechnic, said that while efforts to combat illegal entry should be strengthened, local companies that illegally employ foreigners who have no valid work or residence permits also should be identified.

Government departments should expand investigations of these companies and impose heavier punishments on those that violate the law, he said.

"Those who illegally provide accommodation or bank accounts to foreigners without valid travel documents or whose visas have expired should be seriously punished," he said.

In 2011, the Guangdong government tightened up rules governing foreigners living and working in the province as part of an effort to crack down on illegal immigration and those who overstay their visas and work without permits.

zhengcaixiong@chinadaily.com.cn