Angry fans then clashed, prompting the police to resort to lathicharge.
Hundreds of angry supporters blocked the team bus as the team, who was enjoying a 2-0 lead, conceded an easy draw following Gurpreet's howler.
The East Bengal goalkeeper had to bear the brunt of the fans' wrath as he gave in to his temper showing his middle finger at the crowd.
When contacted, East Bengal general secretary Kalyani Majumdar said: "I'm unaware of the incident."
As lensmen rushed to the spot, angry supporters damaged some cameras.
No official police complaint was however filed.