He also threatened to sit on a 24 hour dharna if the demand for higher compensation was not met but did not specify the date.
The Nitish Kumar government had earlier announced Rs four lakh compensation to the kin of each victim.
Modi, who yesterday visited Katharwa village with a BJP fact-finding team, told reporters that not only the victims of the Bagaha police firing, but also those of Forbesganj, Madhubani and Jai Nagar or anywhere else in Bihar, should be given Rs 10 lakh compensation.
The senior BJP leader, who was the deputy chief minister in the erstwhile NDA government till recently, assailed the police for resorting to 'unprovoked' firing to quell a mob of mostly women and children who were agitating to demand for arrest of the killers of a fellow tribal youth at Bagaha two weeks ago.
"The protesters did not use weapons against the police or indulge in arson of public property. Yet the policemen fired on the mob killing six of them and injuring about 30 others when hardly eight to ten policemen sustained minor injuries during stone pelting by the protesters," he said.