Authorities in Venice, Italy are investigating after a patch of fluorescent green water appeared in the famed Grand Canal on Sunday morning.
"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," Veneto regional president Luca Zaia wrote on Twitter.
The local prefect spokesperson said that they immediately took water samples, reviewed CCTV surveillance tape and asked local gondolier pilots and boat drivers if they saw anything suspicions, before calling an emergency meeting to investigate the cause of the green water, noting that no environmental group had claimed responsibility, CNN reported.
The verdant blob was first noticed around 9:30 a.m. CET and grew slowly, according to multiple images posted on social media, which showed gondolas, water taxis and water bus boats skimming through the emerald substance.
Italy's fire brigade tweeted that they were assisting with providing "samples and technical assistance" to the ARPA Veneto, the regional agency that oversees the environmental state of the Grand Canal, which are "conducting analysis to establish the nature of the substance in the water."