Police in the north Indian state of Uttar Pradesh confirmed six people were killed on Friday during protests against a new ‘anti-Muslim’ citizenship law, the bloodiest day since demonstrations erupted nine days ago.

Protests again raged across much of northern India with people chanting for the prime minister to be removed at Delhi’s Jama Masjid mosque.

Mobile internet has been cut in Uttar Pradesh and it also remains blocked in the southern state of Karnataka after two protesters died in Mangalore.

In total, 15 people have died in clashes while police have detained thousands of protesters and civil rights activists across India.

A video has gone viral on social media of the arrest of historian Ramchandra Guha, the biographer of independence leader Mahatma Gandhi.

Muslims took to the streets en masse after Friday prayers and vowed to demonstrate until Narendra Modi - the prime minister and leader of the ruling Hindu-nationalist BJP - withdraws the controversial Citizenship Amendment Act.

“We will fight till this law is rolled back. We will not back down,” said protester Shamim Qureishi.