Kinshasa, March 19 (IANS): About 600 people abducted in the Democratic Republic of Congo (DRC) by the Allied Democratic Forces (ADF), a Ugandan rebel group, between 2010 and 2013 have not been found till now, a security source said.

The hostages could not be found even after a thorough search in various villages in the country's North Kivu province, Xinhua reported citing Col. Olivier Hamuli, a spokesman of the DRC Armed Forces (FARDC) at Goma in eastern DRC.

At least 600 people were abducted between 2010 and 2013 by ADF rebels in DRC's eastern province of North Kivu.

"We have not found the hostages," Hamuli said, adding that "I think they might have been executed by their kidnappers".

"We do not know whether they were heading to Uganda or they were executed, because ADF's mode of operation is to execute people," he said, noting that the ADF members "were just terrorists".

"But we think there's a high possibility that they were executed because we found some mass graves in some villages. Some of the bodies could have been those of hostages," Hamuli affirmed.

According to North Kivu civil society groups, 893 people have been kidnapped by the ADF, including women and children.

The Congolese army launched an operation Jan 16 against ADF rebels in North Kivu province.