Twenty-one bonded labourers, including some children, were rescued on Friday in a raid by Delhi government authorities at five factories in a north-west Delhi area.
The labourers, hired at a "meagre" salary and working in "hazardous" conditions, were freed from the plastic factories in Narela industrial area.
The raids were conducted by Labour Department officials assisted by police and activists of an NGO Bachpan Bachao Andolan (BBA) after information that several employees in these factories were working as bonded labourers.
Most of the bonded labourers are from Bihar and had come to the capital in search of jobs due to poverty.
"The NGO informed us and a raid was conducted in which 21 people were rescued," Assistant Labour Commissioner N L Kanojia told PTI.
However, as the raiding team began the exercise, some of the labourers were prompted by their employers to run away from the premises. "We suspect that some factory owners had prior information about the raid," Kanojia said.
"We expected to rescue more labourers than what we eventually managed to do. There is information of presence of more bonded labourers in this area, and we plan to conduct more raids in near future," he added.
BBA's Rakesh Senger said these labourers were brought to the capital through middlemen. "They were hired at a meagre salary of Rs 1,000-1,200 and that too wasn't paid to them," he alleged.
The rescued labourers will be temporarily lodged in local police station before Sub Divisional Magistrate Vijay Dogra examines their whereabouts and decide upon repatriation and rehabilitation, Kanojia said.