By Jonathan Saul and Catherine CartierLONDON, Aug 12 (Reuters) - A vast oil spill from a leaking tanker has started to hit Oman's coastline, its environment agency confirmed on Wednesday, in what threatens to become one of the world’s worst in years after spreading largely unchecked for weeks.The oil could end up impacting 40 km (25 miles) of coast near Ras Madraka as well as Masirah Island, the agency said.The slick now covers an area of more than 2,000 square km, said John Amos, an oil spill specialist who reviewed satellite imagery obtained by Reuters.

Oman battles a 390 sq km oil slick from the grounded Caroline Bezengi, using satellites, aircraft and marine surveys to track pollution and protect sensitive coasts.

The Caroline Bezengi's crew first reported difficulties on June 8 off the southern Yemeni port of Mukalla, two maritime security sources said, adding that initial assessments…

Leak area widens after unexplained blast on sanctioned Caroline Bezengi