India on Monday revoked the special status of Kashmir, the Himalayan region that has long been a flashpoint in ties with neighbouring Pakistan, moving to grasp its only Muslim-majority region more tightly.
In the most far-reaching political move in one of the world's most militarised regions in nearly seven decades, India said it would scrap a constitutional provision that allows the state of Jammu and Kashmir to make its own laws.
"The entire constitution will be applicable to Jammu and Kashmir," Interior Minister Amit Shah told parliament, as opposition lawmakers voiced loud protests against the repeal.
United Nations Secretary-General Antonio Guterres urged India and Pakistan, which also claims Kashmir, to exercise restraint. The U.S. State Department said it was closely following the events and expressed concerns over reports of detentions.
Foreign ministry officials briefed envoys of several countries on the changes to the state's administrative status, saying they were aimed at promoting good governance, social justice and economic development.
The government also lifted a ban on property purchases by non-residents, opening the way for Indians to invest and settle there, just as they can elsewhere in India. The measure is likely to provoke a backlash in the region.
Pakistan said it strongly condemned the decision, which is bound to further strain ties between the nuclear-armed rivals.
Pakistan Prime Minister Imran Khan said the move "was in clear violation of the United Nations Security Council (UNSC) resolutions" in the region, according to a statement released after a telephone call with Malaysian Prime Minister Mahathir Mohamad on Monday evening.
"As the party to this international dispute, Pakistan will exercise all possible options to counter the illegal steps," its foreign ministry said in a statement.
India and Pakistan have fought two of their three wars over Kashmir, where a nearly 30-year armed revolt has killed tens of thousands of people. Hundreds of thousands of Indian troops have been deployed to quell it.
India blames that rebellion on Pakistan, which denies the accusation, saying that it backs the right to self-determination for Kashmir.
Hours earlier the Indian government launched a security crackdown in the region, arresting local leaders, suspending telephone and internet services, and restricting public movement in the main city of Srinagar.
Local TV channels citing Press Trust of India reported that former Kashmiri chief ministers Mehbooba Mufti and Omar Abdullah had been detained at a state guest house.
Regional leaders have previously said stripping Kashmir's special status amounts to aggression against its people.
Srinagar's streets were largely deserted as travel curbs kept people indoors, said a Reuters photographer who found a telephone connection in a restaurant near the city's airport.
There was heavy deployment of security forces across the city, but no signs of protest.
"We urge all parties to exercise restraint," U.N. spokesman Stephane Dujarric told reporters, adding that U.N. peacekeepers observing a ceasefire between India and Pakistan in the state of Jammu and Kashmir "has observed and reported an increase in military activity along the line of control."
State Department spokeswoman Morgan Ortagus also called on both sides to "maintain peace and stability along the line of control" and added: "We note that the Indian government has described these actions as strictly an internal matter."
A top government source in New Delhi told reporters the restrictions were precautionary, adding that life was expected to return to normal fairly soon.
Prime Minister Narendra Modi and his Hindu nationalist Bharatiya Janata Party (BJP) had pushed for radical political change in Kashmir even before he won re-election in May, saying its laws hindered integration with the rest of India.
"Politically, it's advantage BJP," said Happymon Jacob, a professor at Jawaharlal Nehru University in the Indian capital.
"The scrapping of Article 370 of the constitution is likely to set off a slew of political, constitutional and legal battles, not to speak of the battles on the streets of Kashmir."