Thousands of volunteers and soldiers are helping to clear the pollutant which is damaging wildlife.
Israel is trying to track the source of the pollution, which is thought to have come from a ship spilling oil.
The general population has been told to avoid the beaches.
Dozens of tonnes of tar have been found on many stretches of Israel’s 190km (120 miles) Mediterranean coastline and there are fears it will take months, or even years to clean up.
NGOs have reported turtles and birds covered in oil.
The pollution is “one of the most serious ecological disasters” in Israel’s history, according to the Nature and Parks Authority.
The source is thought to be an oil spill produced during a storm on 11 February from a ship some 50km (30 miles) off the coast. Satellite imagery and wave patterns are being used to trace the ship responsible.
Environmental Protection Minister Gila Gamliel said nine ships were being investigated.
The Israeli government is considering legal action to win compensation which could run to millions of dollars.
Prime Minister Benjamin Netanyahu has been inspecting the damage at one of the beaches.
Last Thursday, a 17m-long (55ft) fin whale was found dead on a beach in southern Israel, and the Nature and Parks Authority said an autopsy had found an oil-based product – a black liquid – in its system.
However, an official said it was too early to say whether the liquid came from the same oil spill.
Courtesy: AP News