Spanish authorities have declared an environmental emergency after a ship spilt fuel oil during a bunkering operation in the Canary Islands.

A slick forced the closure of several beaches on the island of Gran Canaria following the incident on Wednesday night.

Emergency services said on X that they were alerted late on Wednesday about an “accidental” spill during a refuelling operation at La Luz terminal in the Port of Las Palmas, the island’s capital.

As much as three tonnes of IFO 180, a very low-sulphur fuel oil, were lost into the sea.

The name of the vessel has not been disclosed.

Reuters reported the president of Gran Canaria’s governing council, Antonio Morales, as saying an oil slick 2 km long and 400 metres wide was moving south towards Telde, pushed by winds.

Currents were so far preventing it from affecting a nearby drinking water production plant, but it was still unclear whether the oil would reach land, Morales added.

The beaches of La Restinga, Palos, San Borondon and El Barranquillo were closed to the public as the oil approached the coast.

Photos showed two emergency response boats heading to the scene. A helicopter and drones were also helping with the clean-up operation.

“This contamination sadly has a considerable magnitude, which is why so many resources have been deployed,” Telde’s mayor, Juan Antonio Pena, told Reuters.

“Something like this is preventable. We will demand accountability, because it harms the environment and we cannot allow it to ever happen again.”