The top court in India's most populous state ordered authorities on Monday to remove large displays of the names, pictures and addresses of dozens of anti-government protesters, amid fears that they encourage attacks by vigilante mobs.

The government of Uttar Pradesh in northern India put up six hoardings last week in prominent places in Lucknow, the state capital, identifying people it says joined in violent protests against a new citizenship law based on religion.

Allahabad High Court in Uttar Pradesh ordered the state government to remove the posters by March 16, saying they were "an unwarranted interference in [the] privacy of people".

The state government, run by an ally of India's Hindu nationalist Prime Minister Narendra Modi, will comply with the court order but is considering its "legal options", the chief minister's top adviser, Mrityunjay Kumar, said.

The state government accuses the 57 people depicted in the posters of rioting in December, though none has been convicted of any crime. Those depicted accuse the authorities of trying to "name and shame" the protesters.

Hundreds of thousands of people have held demonstrations across India since late last year to protest against the citizenship law, which they say discriminates against Muslims.

Modi's ruling Bharatiya Janata Party says the law is required to protect non-Muslim refugees across South Asia.

ENDANGERING LIVES

Criticising the posters, Sadaf Jafar, the only woman to appear in them, told Reuters: "The action by the police and administration has made our lives more vulnerable. How will we feel secure in our city?"

Jafar said she was considering taking legal action against the government.

While it was not possible to verify the religion of those featured in the posters, the majority had names commonly used by India's minority Muslim population.

The actions of the government are "totally illegal", said SR Darapuri, a former police officer who also appeared on the billboards for supporting the protests.

"We are not absconders or hardcore criminals," he said. "The government by this act has put our lives in danger."

The adviser, Kumar, has previously defended the billboards, saying they are an attempt to recover damages from those accused and insisting on their legality.

India's demonstrations have spurred often-violent clashes between protesters and police, some along sectarian lines, in which more than 70 people have died, a majority in last month's bloodletting between Hindus and Muslims in the capital Delhi.