India's government has revoked the part of the constitution that gives Indian-administered Kashmir special status in an unprecedented move likely to spark unrest, reports BBC.
Article 370 is sensitive because it is what guarantees significant autonomy for the Muslim-majority state.
The entire region is disputed between India and Pakistan. Each claims it in full, but control only parts of it.
There has been a long-running insurgency on the Indian side.
India and Pakistan, both nuclear powers, have fought two wars and a limited conflict over the Himalayan territory since the independence and partition of India in 1947.
Pakistan has condemned India's decision to revoke the special status of its part of Kashmir as illegal, saying it would "exercise all possible options" to counter it.
"India is playing a dangerous game which will have serious consequences for regional peace and stability," said Foreign Minister Shah Mehmood Qureshi.
The move by the Hindu nationalist BJP government prompted outrage in parliament, and some legal experts have called it an attack on the constitution.
The state's former chief minister, Mehbooba Mufti, has said the revocation of Article 370 would have serious implications not just for the state, but also for the whole country and subcontinent.
Speaking to the BBC, Ms Mufti said she felt there was a "sinister design" to the decision.
"They just want to occupy our land and want to make this Muslim-majority state like any other state and reduce us to a minority and disempower us totally."
She added Article 370 was not given to the people of the state as a "gift", but "a matter of constitutional guarantees given by the very same Indian parliament to the people of Jammu and Kashmir".
What is Article 370?
During the partition of the Indian subcontinent in 1947, Jammu and Kashmir, like other Muslim-majority regions, was expected to go to Pakistan.
But the ruler of the princely state, who had initially wanted Jammu and Kashmir to become independent, joined India in return for help against an invasion of tribesmen from Pakistan.
In 1949, a special provision was added to the constitution providing autonomy to Jammu and Kashmir.
Article 370 allows the state to have its own constitution, a separate flag and independence over all matters except foreign affairs, defence and communications.
Another provision later added under Article 370 - 35A - provides special privileges to permanent residents, including state government jobs and the exclusive right to own property in the state.
It is seen as protecting the state's distinct demographic character as the only Muslim-majority state in India.
These benefits will be lost with the repeal of Article 370.
What did the Indian government do?
It announced a presidential order revoking all of Article 370 apart from one clause which says that the state is an integral part of India. It also proposed to divide the state into two regions.
Home Minister Amit Shah introduced the order in parliament amid massive protests from the opposition.
He said it would become law as soon as it was signed by the president, as revoking the article only required a presidential order.
Soon after the announcement, the Ministry of Law and Justice released an unsigned presidential order spelling out the details of the proposed changes.
It has now been signed into law by President Ram Nath Kovind.
Changing Article 370 also requires the assent of the state government, but Jammu and Kashmir has been under the rule of a governor since June 2018 when the BJP pulled out of a state government coalition with the regional People's Democratic Party (PDP).
This effectively means the state has been ruled directly by Delhi through a governor, who has agreed to the bills.
India's relationship with Kashmir has changed irrevocably
Analysis by Geeta Pandey, BBC News, Delhi
The unprecedented security blanket that the state of Jammu and Kashmir was put under in the last few days indicated that something huge was under way.
Most of the speculation was that Article 35A, which gives some special privileges to the people of the state, would be revoked.
But Prime Minister Narendra Modi's Hindu nationalist BJP government stunned everyone by revoking almost all of Article 370, which has been the basis of Kashmir's complex relationship with India for seven decades.
For many Kashmiris, it was the main justification for being a part of India. By revoking Article 370, the BJP has irrevocably changed India's relationship with Kashmir.
The BJP has long opposed Article 370 and revoking it was part of the party's 2019 election manifesto. After winning a massive mandate in the April-May general elections, it has lost no time in acting on its pledge.
But the decision is definitely not going to go down well with the people of Kashmir.
What has been happening in Kashmir?
Indian-administered Kashmir, home to about 12 million people, is in a state of lockdown.
Curfew-like conditions have been imposed, and orders preventing the assembly of more than four people have been introduced.
Tens of thousands of Indian troops were deployed to the region ahead of Monday's announcement and tourists were told to leave under warnings of a terror threat.
The restriction of mobile networks and the internet have added to the sense of crisis and largely cut the region off from the rest of India.
In the hours before Monday's announcement, two of the state's former chief ministers - Omar Abdullah and Mehbooba Mufti - were placed under house arrest.