A policeman escorts an illegal immigrant with location not revealed, March 25, 2016. [Photo/IC]

BEIJING - Mainland and Hong Kong police have arrested 2,943 illegal immigrants in a joint operation to crack down on growing human smuggling, the Ministry of Public Security said Wednesday.

Among the detained immigrants, 2,860 are from Southeast Asia and 83 from South Asia, said the ministry at a press conference held in Shenzhen of Guangdong.

Most illegal immigrants were trying to sneak into Hong Kong from the mainland to seek employment, it added.

Since the 17-month campaign started on February 20, police in Guangdong, Guangxi and Yunnan have dismantled three cross-border smuggling syndicates with the help of Hong Kong police, the ministry announced the results of the first phase of the crackdown.

A total of 142 suspects from the three syndicates were apprehended by police, including 29 from countries in Southeast Asia and South Asia.

The cross-border smuggling rings are well organized with clear division of labor, said the ministry.

"Smugglers in Southeast Asia and South Asia recruit immigrants, smugglers in the mainland transfer them to Guangdong from the border and ports and then sneak them into Hong Kong, and smugglers in Hong Kong take control of the whole process," it added.

Illegal immigrants have also commit crimes such as thefts, robberies and drug smuggling, which in result seriously harmed public security in both Hong Kong and Guangdong, the ministry said.

The authorities vowed to increase cooperation between police in Guangdong, Guangxi, Yunnan and Xinjiang and step up the joint crackdown on human smuggling, in an effort to safeguard social security and stability.