The Delhi Police registered a case on Sunday after pro-Khalistan slogans were found written on the walls of multiple metro stations in the city, ANI reported.

Reports earlier said that the slogans were found at at least five stations. However, Deputy Commissioner of Police (Metro) G Ram Gopal Naik said that four metro stations have been defaced.

A case was filed based on a complaint filed at the Nangloi police station. The police are investigating the matter and looking into CCTV camera footage, Naik told reporters.

An unidentified senior police officer said that suspected activists of the banned separatist organisation Sikhs For Justice painted the slogans on the walls of metro stations in the stretch between Shivaji Park and Punjabi Bagh, the Hindustan Times reported.

Sikhs For Justice have also released a video of the vandalism, the police officer said.