People in a number of countries in eastern Europe experienced an unusual weather event over the weekend: orange snow.
BBC reports the phenomenon appeared to affect areas of countries including Russia, Bulgaria, Ukraine, Romania and Moldova.
Photos shared on social media showed ski slopes with a distinctly orange hue:
A post shared by Ekaterina Grebnitskaya (@katrin.jd) on
A post shared by Viktor (@victor.teplyakov) on
Steven Keates of the UK's Met Office told The Independent that the phenomenon of orange snow is feasible, and likely a result of sand from the Sahara.
He explained: “There has been a lot of lifted sand or dust originating from North Africa and the Sahara, from sand storms which have formed in the desert. As the sand gets lifted to the upper levels of the atmosphere, it gets distributed elsewhere."
Well done to all those who said Crete. @TootingGareth captured this picture showing the eerie orange glow. Reports also came in from as far afield as Russia and Romania where lying snow had turned yellow and orange! pic.twitter.com/APW9QlbrpU
— Met Office (@metoffice) March 25, 2018
He added that NASA satellite imagery showed sand and dust in the atmosphere, explaining: "When it rains or snows, it drags down whatever is up there, if there is sand in the atmosphere.”
Orange snow was reported in Siberia in 2007, with locals describing a "pronounced rotten smell" - with some theorising pollutants may have been the cause in that case.