Venetian authorities are investigating after part of Venice's water has turned fluorescent green since yesterday morning.
The prefect has called an urgent meeting with the police to investigate the origin of the water.
So far there is still no answer. Monstratce taken from the water are sent to the laboratory.
The phenomenon was first noticed around 9:30 a.m. and slowly grew, according to multiple images posted on social media, which showed gondolas, water taxis and water boats passing through the emerald substance.
City councilor Andrea Pegoraro immediately blamed environmental activists who have attacked Italian cultural heritage sites in recent months.
The Ultima Generazione group, which poured coal into Rome's Trevi Fountain last weekend, told CNN when asked if they were behind the green water, "It wasn't us."
Various theories surfaced online, including that it could be algae or a substance illegally distributed in the canal.
This is not the first time that Venice's Grand Canal has undergone a color change.
In 1968, Argentinian artist Nicolás García Uriburu colored the canal's waters green with a fluorescent dye called Fluorescein, during the annual Venice Biennale. The movement was created to draw attention to ecological issues and the relationship between nature and civilization.
