South Korea has mobilized an army of workers and volunteers to contain an enormous oil spill, which has fouled an environmentally sensitive shoreline.

More than 10 million litres of crude oil gushed from the Hong Kong-registered Hebei Spirit tanker on Friday after it collided with a barge, 11 kilometres from South Korea's western coast.

Local residents carry baskets full of crude oil that washed ashore on Mallipo beach.
(Lee Jin-man/Associated Press)

On Saturday, hundreds of troops, police and residents from Taean region were battling to clean up Mallipo, one of the country's best-known beaches.

South Korea's coast guard also struggled in high waves and strong winds to keep more oil from washing up, placing an eight-kilometre-long boom near the spill and spreading chemical dispersants.

The region, 150 kilometres southwest of the capital Seoul, is popular for its scenic beaches and as a rest stop for migrating birds. It's also home to fish farms and a national maritime park.

Officials are calling this South Korea's worst ever oil spill.

Kim Jong-sik, an official with the ministry of maritime affairs and fisheries, said there are fears the spill could cause an ecological disaster.

"We have set up a boom, trying to stop oil from spreading along the coast, but oil sometimes overflows it depending on the currents," he told Agence France-Presse.

The tanker, the Hebei Spirit, and the other vessel, owned by South Korea's Samsung Corp., were in no danger of sinking, the coast guard said.