Three people died after a "derogatory" Facebook post about Islam sparked riots in India's IT hub Bangalore that saw clashes between police and thousands of protesters, authorities said Wednesday.

At least 60 officers were injured the previous evening as a furious crowd attacked a police station, set vehicles on fire and burnt down the house of a local lawmaker whose nephew was allegedly responsible for the social media post.

Local media images showed protesters trying to barge into the police building and shouting slogans outside the politician's home.

Police opened fire with live ammunition and tear-gassed the violent crowds. Three people were critically wounded during Tuesday's violence and at least one reporter was injured, police told AFP. 

Media reports said the three people killed in the incident had died of gunshot wounds.

Bangalore police commissioner Kamal Pant wrote on Twitter that the lawmaker's nephew had been arrested for the post, along with about 100 others for rioting and arson, and the situation was now under control.

A ban on gatherings was in effect in some areas of the city on Wednesday, with nearly 10,000 police reservists patrolling the streets to keep order.

The deaths were confirmed by the home minister of Karnataka state of which Bangalore is the capital.

The violence started after protesters massed outside the politician's house as well as a police station after spotting the post, which local media say has since been deleted.

Three people have died in the Indian city of Bangalore after police fired on crowds protesting against an allegedly blasphemous Facebook post. Crowds gathered outside the house of a local politician whose relative was accused of making an "offensive" post about the Prophet Muhammad (PBUH).

They set fire to vehicles and attacked policemen who arrived on the scene with stones.

Meanwhile, the minister, Akhanda Srinivas Murthy made a video appeal to protesters to stay calm and promised them justice. "I appeal to my Muslim brethren not to fight over someone who has violated the law. Whatever be the matter, we are all brothers. Whoever is responsible we shall ensure that proper punishment is given to those responsible. I am with you," it said.

Bangalore is known as the Silicon Valley of India and is home to a sizeable Muslim community among its eight million people.

India is officially a secular country but has been plagued by a long history of violence between its Hindu majority and Muslim minority.

More than 50 people were killed during religious riots in the capital New Delhi earlier this year, with most of the victims Muslims.