Spain's government has activated an environmental emergency alert over an oil slick that threatens pristine beaches on the southwestern Canary Islands.

The government activated a level 2 alert after analyzing ocean current data from Spain's Oceanographic Institute, saying the slick that reached coastlines earlier in the week could affect vulnerable land. Level 2 is the second highest alert level.

The government said Saturday one beach has been cleared of oil and clean-up operations are ongoing on three other beaches near the tourist hot-spot of Maspalomas on Gran Canaria.

The Russian trawler Oleg Naydenov, carrying 1,400 metric tons of fuel oil, caught fire in a nearby port on April 11. It was towed out to sea, some 24 kilometers (15 miles) south of the island, where it sank three days later.