India on Thursday urged Pakistan to review its decision to downgrade diplomatic ties over the withdrawal of special status to Kashmir, saying it was an internal affair and aimed at developing the revolt-torn Muslim majority region.
Prime Minister Narendra Modi's Hindu nationalist government revoked the territory's special privileges to frame its own laws and lifted a ban on people from outside the region to buy property there in a bid to tighten its grip.
Pakistan, which also has claims on Kashmir, said it would expel India's ambassador in Islamabad and its envoy, who was to start his assignment soon, would not move to New Delhi.
Islamabad also suspended bilateral trade and on Thursday announced it would shut down the train service to India, in the latest spike in tensions between the nuclear rivals.
"The government of India regrets the steps announced by Pakistan yesterday and would urge that country to review them so that normal channels for diplomatic communications are preserved," India's foreign ministry said, striking a conciliatory tone.
Within Kashmir, authorities kept a communications blackout with mobile networks and internet services suspended since Sunday and detaining at least 300 politicians and separatists to quell protests, according to police, media and local leaders.
Regional leaders have warned of a backlash against Modi's decision to revoke Jammu and Kashmir's decades-old special status and split the state into two federal territories to allow the government greater control.
Thousands of paramilitary police have been deployed in the largest city, Srinagar, schools shut and roads and neighbourhoods barricaded.
There have been sporadic protests, two police officers said, speaking on condition of anonymity. At least 13 people have been injured in stone-throwing protests across the city since Tuesday night, one officer said.
Srinagar's old quarter was locked down on Wednesday evening, with policemen in riot gear deployed every few metres, and barbed-wire checkpoints every few hundred metres.
Near the Jama Masjid, which has long been the centre of protests in Srinagar, bricks and rocks from recent stone pelting incidents were strewn in at least three locations.
A witness said that there had also been stone-throwing in the Bemina area in northwest Srinagar, where some roads had been blocked by poles and boulders.
"There is a lot of anger among the people," one of the police officials said.
Kashmiris see Modi's decision to withdraw the special status as a breach of trust and opening the way to flooding their region with people from the rest of India, eventually altering the demographics of the territory.
Already tens of thousands of people have died in the armed revolt to secede from India that erupted in 1989 and has ebbed and flowed since then.
Two leaders from the National Conference, a major regional party, said at least 100 politicians – including former state ministers and legislators – had been detained. They did not want to be named because of the sensitivity of the information.
Two former chief ministers of the state are among those detained, they said. India's Mail Today newspaper said the number of politicians held in their homes and guesthouses was more than 400.
Mirwaiz Omar Farooq, chairperson of the Hurriyat Conference, an umbrella group of non-violent separatists, has been detained at his home, a statement from his office said.
Pakistani Nobel Peace Prize winner, Malala Yousafzai, called for a peaceful resolution to the conflict in Kashmir.
"The people of Kashmir have lived in conflict since I was a child, since my mother and father were children, since my grandparents were young," she said on Twitter.
"Whatever disagreements we may have, we must always defend human rights, prioritise the safety of children and women and focus on peacefully resolve the seven-decade-old conflict in Pakistan," she added.