Venice: People in Venice woke up to an unusual sight on a Sunday morning after a patch of fluorescent green water appeared in the famed Grand Canal. Veneto regional president Luca Zaia wrote on Twitter, “This morning a patch of phosphorescent green liquid appeared in the Grand Canal of Venice, reported by some residents near the Rialto Bridge. The prefect has called an urgent meeting with the police to investigate the origin of the liquid.” According to a BBC report, local authorities have collected water samples and opened an urgent investigation. Many are speculating what may have caused the water around the famous Rialto Bridge to change colour. Various theories surfaced online, including the release of dye to a protest by environmental activists could be a reason. The Italian media reported that local police were examining CCTV to determine whether the release might have been a stunt to coincide with the Volgalonga regatta taking place this weekend. According to CNN, the verdant blob was first noticed at around 9.30 am CET and grew slowly. City councilman Andrea Pegoraro immediately blamed environmental activists who have been attacking Italian cultural heritage sites in recent months.