URUMQI - China's police are lengthening a project designed to fight rings that coerce children of a remote ethnic region to pickpocket across the country after the crackdown has so far helped free 1,624 children.

Last April, police authorities launched a campaign to address the growing notoriety of children from Xinjiang Uygur autonomous region, especially the predominantly Uygur rural areas, being conned to form the armies of "young thieves and beggars" familiar to many city dwellers.

Zhao Peixin, a senior police official from Xinjiang Uygur autonomous region, told Xinhua Friday that the Ministry of Public Security has allowed the campaign, originally scheduled to wind down at the end of 2011, to continue until the end of May in order to "completely curb the crime."

He said high profit is fueling the growth of child pickpocket rings, which are increasingly becoming family-based syndicates. Children who were not obedient or ran away were beaten, some to their deaths.

Zhao said ring members usually faced a series of charges -- murder, abduction, robbery, theft, fraud, gambling, and drug-related crimes. During last year's campaign, police arrested 1,630 suspects and busted 227 rings.

In the coming months, police will conduct a blanket investigation in the rural southern Xinjiang regions of Aksu, Kashgar and Hotan to gain knowledge of how many children remain missing, Zhao said.

"We will not relent until all abducted children are found," he added.