Seven people were beaten to death by a violent mob in two separate incidents in Jharkhand's Singhbhum district, police said.
Rumours circulated on WhatsApp, according to the police, led to the "unfortunate and unprecedented" incidents.
Of the seven victims, Vikas Kumar Verma, Gautam Kumar Verma and Gangesh Gupta, were beaten to death in Nagadih. An elderly woman was also brutally assaulted in the incident. Whereas four people were killed in Shobhapur and Sosomouli villages after locals suspected them to be members of a kidnapping gang, a senior cop said.
The last images of one of the victims in Shobhapur, Mohammed Naeem, show him lying on the road soaked in blood and pleading for his life.
"A civilised society cannot allow such heinous crimes to occur where human lives are taken by angry mob merely on suspicion of them being anti-social elements," the NHRC said in a strongly-worded statement.
On Saturday, hundreds of villagers clashed with the police in Jamshedpur to protest against the killings. Cops had to resort to lathi-charge and use of tear gas to control angry protesters.
The commission has also asked for suggestions and preventive measures that can be taken to ensure that such incidents do not reoccur," the NHRC added.
Reacting strongly to the incident, Jharkhand Chief Minister Raghubar Das directed authorities to identify and act against the accused.
The cops are trying to find the origin of the WhatsApp messages and claim to have identified suspects. So far, 18 people have been arrested for the killings and the violent clashes that broke out in their aftermath.
(With inputs from PTI)