Just days ahead of Republic Day, pro-Khalistan graffiti was found written on the wall of a government school in west Delhi's Uttam Nagar area, the police said on Friday.
The slogan "Khalistan SFJ Zindabad" written on the wall came to notice on Thursday night, they said.
A senior police officer said a case was registered in Dwarka district under section 3 of the Delhi Prevention of Defacement of Property Act.
Several teams of the district, including special staff, are working on the case to nab the accused, the officer said, adding that CCTV footage of the area was being checked.
Pro-Khalistan leader Gurpatwant Singh Pannun, the chief of the banned Sikhs for Justice, released a video after the incident.
This is the second such incident to take place in less than three days.
On January 16, similar graffiti was found on a pillar in west Delhi's Nihal Vihar. The graffiti read "SJF, January 26, Khalistan".
Pannu had released a threatening video then as well. -- PTI