By Subir Bhaumik
BBC News, Calcutta
Indian police say they have shot dead 12 protesters during student demonstrations in the north-eastern state of Meghalaya.
Police say they opened fire when students attacked them with stones, injuring some officers.
Protest leaders say the police opened fire without provocation.
Students from the Garo tribe have been staging protests against planned educational reforms that have created divisions with the Khasi tribe.
The protests took place in the towns of Tura, in West Garo Hills, and Williamnagar, in East Garo Hills.
An indefinite curfew has been imposed in both places, Meghalaya's Home Minister, Mukul Sangma, told the BBC.
He said the army had now been called in to the two Garo Hills districts to try to control the violence.
Police had earlier said only six people had died.
The deputy inspector general of the Garo Hills range, Vijay Kumar, told the BBC from Tura that the Garo Students Union (GSU) was not given permission to hold a rally.
Despite that, he said hundreds of people gathered in Tura for the rally.
When the police arrived, the crowd threw stones injuring some policemen, he said.
The police and paramilitary soldiers then opened fire in retaliation, Mr Kumar said. He said seven people had died in Williamnagar and five in Tura.
Overstone Marak, convenor of the Garo Citizens' Committee, the organisation jointly leading the protest campaign in Meghalaya, said: "Police opened fire on the agitators without any provocation and without resorting to baton charging first - which is the normal practice."
The GSU began a campaign of protests earlier this month against the state government's proposed educational reforms.
The government has asked the student body to end its protest actions before it negotiates over the reforms.