CHENNAI - Police in the south Indian city of Bengaluru have broken up an international child trafficking racket and arrested 16 members of a gang suspected of sending children illegally to the United States, an investigating officer said on Tuesday.

The syndicate sent at least 25 children to the United States using false documents before the special investigative team made the arrests, he said. The breakthrough comes at a time of mounting concern over the rise in human trafficking in India. National Crime Record Bureau data show that human trafficking, mainly for sexual exploitation, rose 60 percent between 2010 and 2014.

Agents of the syndicate sent children below the age of 10 to Bengaluru from the northern states of Bihar and Uttar Pradesh and the western state of Gujarat, the NDTV news channel reported. The children then joined adult couples and were made to pose as a family travelling to the United States, presenting false documents at the US Consulate in Chennai, in southeast India, to get permission for the journey, it reported. The adult couple flew to the United States with the children, left them there and returned to India, it said.

Investigating officer P Harishekaran said the arrests followed a year-long investigation, which included going through immigration records of the two countries.

Questioned by the police, the suspected traffickers said they were reuniting the children with their parents in the United States, all illegal immigrants, NDTV reported. But it quoted police officials as saying they believed the children were being sold in the United States.

The investigation continues and the suspected traffickers are being held for further questioning, police said.