Violence against Muslims has escalated in India over the last few days, including an incident where an Indian Railway worker killed four people and praised Prime Minister Narendra Modi.

The suspect, Chetan Singh, is accused of shooting a colleague and three Muslim passengers - Abdul Kadar, Asgar Abbas Ali and Syed Saifullah.  

Footage shared on social media showed Singh with a gun, standing next to a blood-soaked body.  

"If you want to live and vote in Hindustan [India], I am telling you, it's only Modi and Yogi," he was heard saying in one of the videos verified by Al Jazeera.

The shooting has been widely condemned, with Asaduddin Owaisi, a member of parliament and leader of the All India Majlis-e-Ittehad-ul-Muslimeen party, calling it a "terror attack that specifically targeted Muslims".

Jairam Ramesh, a senior leader from the opposition Indian National Congress party, denounced it as "cold-blooded murders."

"The genie of hate is now out of the bottle and it will take a lot of collective effort to put it back in," Ramesh said in a tweet, laying the blame for "hate and violence" on Modi's Bharatiya Janata Party (BJP).

He added that top leaders were "complicit in damaging the social fabric of India."

Imam killed after mob attack on mosque

On Tuesday, a mob of far-right Hindus attacked a mosque in a suburb of New Delhi, killing the deputy imam, hours after deadly communal violence in a nearby district.

Maulana Saad, 19, led prayers at Anjuman Jama mosque in Gurugram. One other person was injured in the incident.

Hindu extremists aligned with the ruling Bharatiya Janata Party (BJP) have been protesting against Friday prayers in the district. The Anjuman mosque is one of the few places officially to hold such prayers.

"A group of 50 to 60 miscreants resorted to firing and arson at Anjum in the early hours of Tuesday, which led to the death of one person and wounded another," said deputy commissioner of Police Nitish Agarwal.

"We have arrested a few people, registered an FIR [police report] against them and have launched an investigation into the incident," Agarwal added.

Gurugram remained tense as mobs roamed the streets, setting fire to shops and vandalising eateries, many of which belonged to Muslims.

The incident comes after violence erupted in neighbouring Nuh during a religious procession by Hindus in the Muslim-dominated Nuh district.

Four people, including two police personnel, died and around 60 others were injured.

Tensions arose when a video emerged from a prominent cow vigilante, Monu Manesar, who said he would attend the procession.

Manesar regularly shares videos of himself interrogating cattle transporters, who have in recent years been assaulted by Hindu extremist groups.