Authorities in Kashmir have arrested nearly 4,000 people since the scrapping of its special status on August 5, government data shows, the most clear evidence yet of the scale of the crackdown.

Kashmir has been in turmoil since the decision, leading to clashes between security forces and residents.

In an attempt to stifle the protests, the government has arrested more than 3,800 people, according to a government report dated September 6 and seen by Reuters, though about 2,600 have since been released.

A spokesperson for the Union home ministry did not respond to a request for comment. Neither did Jammu and Kashmir police.

It was not clear on what basis most of the people were being held but an official said some were held under the Public Safety Act, a law that allows for detention for up to two years without charge.

The data for the first time shows the extent of the detentions, as well as indicating who was picked up and where.

More than 200 politicians, including two former chief ministers, were arrested along with more than 100 leaders and activists from an umbrella organisation of pro-separatist political groups.

The bulk of those arrested — more than 3,000 — were listed as “stone pelters and other miscreants”. On Sunday, 85 detainees were shifted to a jail in Agra, a police source said.

Rights group Amnesty International said the crackdown was “distinct and unprecedented” in the recent history of the region and the detentions had contributed to “widespread fear and alienation”.

“The communication blackout, security clampdown and detention of the political leaders in the region has made it worse,” said Aakar Patel, head of Amnesty International India.

The government says the detentions are necessary to maintain order and prevent violence, and points to the relatively limited number of casualties compared with previous bouts of unrest.

The report contains data from the 13 police districts that make up the Kashmir Valley. The largest number of arrests have been in Srinagar, the data shows, at nearly 1,000. Earlier unrest often centred on rural areas.

Of the detained political leaders, more than 80 were from the Peoples Democratic Party, about 70 from the National Conference, and over a dozen from the Congress.

Police also arrested more than 150 people accused of association with militant groups.

An official said it was likely that more than 1,200 people were still held, while dozens more are being arrested every day. In the 24 hours before the report was compiled, more than two dozen people were arrested, the data showed.

The data did not include those under informal house arrest, nor people detained in a round-up of separatists that began in February after the Pulwama attack.

Days before the move to strip Kashmir of its special status, one prominent separatist leader had told Reuters that more than 250 people with links to the movement were already in detention.