Violent clashes erupted between protesters and police in Kashmir on Friday, after days of unrest in the Himalayan region over the killing of a youth by the army and a crackdown by authorities on separatist leaders.
Police fired tear gas and charged with batons to disperse hundreds of people who gathered after Friday prayers in the main city Srinagar to protest the arrests of the leaders and the killing of the youth, a militant commander's brother, earlier this week.
Several protesters and police were injured in the clashes, police said.
The unrest is the latest challenge for Prime Minister Narendra Modi's Hindu nationalist BJP, which this year took control of the Kashmir government in alliance with a regional partner, the first time it has been in power in the state.
Police arrested separatist leader Masarat Alam on Friday morning, a month after his release from prison. He had been in jail for five years for organising anti-Indian protests that swept through Kashmir in 2010.
Alam is accused of joining a rally earlier this week at which some people waved Pakistani flags, angering Indian politicians.
"I want to assure the people of this nation that those involved in treason will not be spared," India's home minister Rajnath Singh told reporters on Friday when asked about the arrests.
Singh had called Kashmir's Chief Minister Mufti Mohammad Sayeed on Thursday demanding the "strictest possible action" against those involved in the rally.
Police also put another separatist leader Syed Ali Geelani under house arrest to prevent him from leading Friday's march.
Kashmir has been divided between India and Pakistan since a war after independence from Britain in 1947. The nuclear-armed neighbours have fought two of their three wars over the territory.