Indian authorities on Saturday restored internet in Indian Kashmir after a five-and-a half-month blackout but maintained a block on social media sites.

Prime Minister Narendra Modi's government imposed a communications blackout in early August when it stripped the portion of Kashmir it controls - the country's only Muslim-majority region - of its partial autonomy.

India also imposed a curfew, sent in tens of thousands of extra troops and detained dozens of Kashmiri political leaders and others, many of whom remain in detention, drawing criticism abroad.

Internet access was restored Saturday but only to 301 government-approved websites that include international news publications and platforms such as Netflix and Amazon.

Mobile phone data access was also restored, although it was limited to slower second-generation (2G) connections.

"It's good some internet access has been restored but it's so slow I'm hardly able to access anything and social media is also off-limits," Raashid Ahmad, a university student, told AFP.

Azhar Hussain, a local businessman, also complained about the internet speed being "painfully slow".

India is the world leader in cutting internet services, activists say, and access was also temporarily suspended in other parts of the country during recent protests against a new citizenship law.

Since August freedom of movement in heavily-militarised Kashmir has been gradually restored as has cellphone coverage, but apart from at a handful of locations, there has been no regular internet access.

This made life even harder for the region's seven million inhabitants and hit the local economy hard.

Modi's government said that the blackout was for security reasons, aimed at restricting the ability of armed militants - who it says are backed by arch-rival Pakistan - to communicate.

However, the Supreme Court criticised the government earlier this month for the move, calling it an "arbitrary exercise of power".

The court also stated that having access to the internet "is integral to an individual's right to freedom of speech and expression".

Kashmir has been divided between India and Pakistan since independence in 1947, and has been the spark of two wars and numerous flare-ups between the two nuclear-armed foes.

A bloody insurgency against Indian rule that has raged in the scenic Himalayan region for decades has left tens of thousands dead, mostly civilians.