Indian authorities have prevented an award-winning photographer from flying to the United States to collect her Pulitzer Prize, the latest of several Kashmiri journalists barred from leaving the country.

Sanna Irshad Mattoo was one of four journalists working for Reuters news agency that took home the prestigious award for feature photography this year.

The 28-year-old has won plaudits for documenting life in Indian-administered Kashmir, a disputed and highly militarised Himalayan territory home to a decades-old insurgency.

Mattoo was stopped by immigration authorities at New Delhi airport late Tuesday and prevented from boarding while two of her colleagues were permitted to leave the country.

She later tweeted a picture of her ticket that was stamped "cancelled without prejudice".

"I don't know what to say... this was a once-in-a-lifetime opportunity for me," Mattoo, who is also a fellow of the prestigious Magnum Foundation, told AFP.

"Only I was stopped without any reason and the others were allowed to go. Maybe it has something to do with me being a Kashmiri."

Tuesday was the second time this year that Mattoo was prevented from leaving India.

In July she was stopped in a similar manner at the same airport while on her way to Paris for a book launch and photography exhibition.

India has sought to entrench its control of Kashmir, which is also claimed in full by neighbouring Pakistan and which has been a constant source of tension between the nuclear-armed archrivals.

Thousands have been killed there since the start of a rebellion against Indian rule in 1989, and more than half a million troops are permanently stationed in the region.

Prime Minister Narendra Modi's government stripped the territory of its limited autonomy in 2019, severing internet connections for months and detaining political leaders to forestall an anticipated backlash.

Foreign journalists have been barred from Kashmir and local reporters based in the territory say they have come under pressure to tone down their work.

- 'Arbitrary and excessive' -

Several other Kashmiri journalists have also been preventing by authorities from travelling abroad in the past three years.

Independent journalist Aakash Hassan, a regular contributor to the Guardian newspaper, was not allowed to board a flight from New Delhi to Sri Lanka for work in July.

He told AFP that months later, he has still received no information from authorities as to why he was denied permission to travel.

"Given the pattern, it looks like it only happens to Kashmiri journalists," Hassan told AFP.

The decision to prevent Mattoo from leaving was "arbitrary and excessive", Beh Lih Yi of the Committee to Protect Journalists said in a statement.

She called on India to cease "all forms of harassment and intimidation" against journalists working in Kashmir.