An FIR was registered against an unidentified individual at a cybercrime station in Uttar Pradesh`s Prayagraj after a social media post vowed to take "revenge" for the killing of gangster Atiq Ahmed, police said.

According to an FIR registered by Prayagraj Police on the complaint of an individual identified as Mohammad Alamgir, the post was made by a Twitter handle by the name of `The Sajjad Mughal`.