New Delhi | A fresh case has been registered after posters were allegedly pasted and black ink was used to write on walls at Shivaji Stadium Metro station on the Airport Express Line, police sources said.

The incident took place on October 24, when posters were allegedly found pasted on a wall near Emergency Gate No. 5, while some writing in black ink was noticed on a shaft wall near Gate No. 7, they said.

The IGI Airport Metro Police have registered a case against an unidentified person under the Delhi Prevention of Defacement of Property Act and the Metro Railways Act.

The latest incident comes days after two posters questioning the Centre's performance over the past few years were found pasted inside a train on the Airport Express Line.

The earlier incident came to light on October 20, when a train operator noticed the posters on a seat while inspecting the train after it reached Yashobhoomi station from New Delhi, according to the police complaint.

The posters, printed in black and white on A4-sized sheets, raised various issues and invited people to join an online group through a QR code. One of them carried the heading "Dissatisfied? You Are Not Alone" and listed nine claims about changes in the country over recent years, while the other called for collective engagement and community building.

The posters were removed and handed over to the police, who registered a case against unidentified persons. The Special Cell was also involved in the investigation, police sources had said.

Further investigation into the latest incident is underway, police said.