Authorities in Venice, Italy, are investigating the source of a mysterious green liquid patch that appeared Sunday in the city’s Grand Canal.
Images from the local fire department showed a fluorescent patch, similar to the color thrown into the Chicago River every St. Patrick’s Day, spreading through the water near the arched Rialto Bridge.
While officials saythe liquid appears to be an "organic compound used for water inspections or in caving," and doesn't pose a danger of pollution, as of Monday, officials still had no idea where the color was coming from.
"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.
Officials have already taken water samples and are now reviewing surveillance footage.
Environmental activist groups have recently attacked historical sites in Italy.
Last week, activists poured diluted charcoal into the Trevi Fountain in Rome and turned its blue water black,CNN reported.
So far, none of the groups have claimed responsibility for the green liquid.
SEE MORE: UN report: We're losing progress in fight against climate change
Trending stories at Scrippsnews.com