Russian scientists sounded the alarm Wednesday over a huge oil slick in the Black Sea, with the World Wildlife Fund saying at least 100 tonnes of oil have leaked off the city of Novorossiysk.
A leak occurred at a sea terminal near the southern port city at the weekend as the Greek-flagged Minerva Symphony was loading oil.
On Monday, the Caspian Pipeline Consortium (CPC), which controls the terminal, said the spill was contained, estimating that oil had spread over an area of 200 square metres (2,150 square feet) and involved around 12 cubic metres (423 cubic feet) of oil.
By early Sunday, "the situation was back to normal" and posed no threat to either the local population or wildlife, said the consortium.
CPC is owned by a number of shareholders including Russia's Rosneft, US oil giant Chevron and Italy's Eni.
But the WWF and Russian scientists said Wednesday the oil slick was much larger than initially reported and could have a negative impact on the environment.
The conservation group said it had launched its own surveillance and citing its own data found the slick had covered an area of 94 square kilometres by Sunday.
'COLOSSAL' AREA AFFECTED
The WWF estimated that at least 100 tonnes of oil -- "and most likely even more" -- had been released into the Black Sea.
"Despite the prompt involvement of rescue teams, the oil spread over a colossal area," the WWF said in a statement on Facebook, adding that marine wildlife could be affected.
Aleksei Knizhnikov, head of the responsible industry programme at WWF Russia, said the slick was drifting north, having already reached Abrau-Dyurso famed for its beaches and wine-making industry and might later reach the Utrish Nature Reserve.
Speaking to AFP, Knizhnikov said it was too early to say how the slick could affect the environment.
"We can say that there is no objective information about the scale of the spill on the part of regulatory authorities," he added.
The Space Research Institute of the Russian Academy of Sciences said it was also monitoring the pollution and citing data from satellite images said earlier in the day that the oil had spread over an area of nearly 80 square kilometres.
"On August 8, the oil slick spread from the shore into the open sea over a distance of 19 kilometres," the institute said in a statement.
On Wednesday afternoon, investigators said a pollution probe was underway.
