A massive oil spill caused by leakage from a power plant inside one of Syria’s oil refineries is spreading along the coast of the Mediterranean country, Syria’s state news agency said.

SANA said the spill reached the coastal town of Jableh, about 20 kilometres (12 miles) north of the refinery in the town of Baniyas, adding that Syria’s environment department and the municipality of the coastal province of Latakia have placed all concerned departments on alert.

It said work is under way to clean the coast in the rocky areas.

A day earlier, Syria’s government said that maintenance teams at Baniyas Thermal Station had brought a fuel leakage from one of the tanks under control.

Satellite images from Planet Labs on Wednesday showed what appeared to be a massive oil spill stretching out over 25.5 square kilometres.

An image from Monday showed no sign of the slick, suggesting whatever happened to cause the spill happened later.

The head of the Electricity Workers Syndicate at Tartous Workers Union, Dawoud Darwish, blamed cracks in one of the fuel tanks at the thermal station.

He pointed out that the tank was filled with 15,000 tons of fuel.

Syria’s oil resources are mostly outside of government-controlled areas but its two refineries are under government control and operating.

This makes Damascus reliant on Iran for fuel, but US Treasury sanctions have hindered the supply network, which spans Syria Iran and Russia.

There have been a series of attacks on vessels in Middle East waters, including off Syria’s coast, for more than a year.

They have come amid rising tensions in the region between Iran, Israel and the United States.

In May, Syria’s foreign minister blamed Israel for mysterious attacks targeting oil tankers heading to Syria, saying they violate international law and will not go unpunished.