NEW DELHI, June 12 (Xinhua) -- Indian police have arrested some 40 people in northeastern state of Assam for spreading rumors about child lifters and hate messages on social media.

"The arrests came in the aftermath of Friday night's horrific lynching of two youths in Assam. These arrests are separate from the 25 people held so far for the lynching of the duo in Karbi Anglong district," a police official told the media Tuesday.

A mob of hundreds had beaten to death the duo- Niloptal Das, a 29-year-old sound engineer, and 30-year-old Abhijeet Nath, while they were on an adventure tourism in a village in Assam's Karbi Anglong, 200 km from capital Guwahati, suspecting them to be child-lifters.

"A massive manhunt is on to nab other accused in the lynching case," local police chief G.V. Siva Prasad told the media Monday.

State Chief Minister Sarbananda Sonowal has issued a stern warning to people spreading fake rumours on social media. "People found circulating rumours would be dealt with very firmly," he told the media in Guwahati after holding a high-level security meeting Sunday.