Tens of millions of fish were killed in one of Vietnam's biggest environmental disasters, which was caused by a unit of Taiwan conglomerate Formosa Plastics.

The protesters, many of them fishermen, had planned to travel from central Nghe An province to submit their claims in Ha Tinh, where the company is based, about 180 km (112 miles) to the north.

But activists said police stopped the protesters' vehicles, and later stopped them, after they had walked 20 km (12 miles) towards their destination.

Nghe An police said they could not immediately provide any information on the matter. Nghe An provincial officials were not available for comment.

Witnesses said police had beaten and arrested some of the protesters.

"Police beat me, they caused a few scratches," Nguyen Dinh Thuc, a priest leading the group, told Reuters by telephone.

Formosa Ha Tinh Steel paid $500 million in compensation and said its steel plant had killed fish along a 200-km (120-mile) stretch of coastline, though not reaching as far as Nghe An province.

Last September, hundreds of lawsuits were submitted by fishermen seeking to sue the Formosa subsidiary. But state media said the claims had been rejected by a court.

The pollution sparked an unprecedented run of protests, a challenge for a communist government that is known for suppressing dissent and rarely faces large demonstrations.

Authorities have accused anti-government groups of trying to exploit the disaster and stir up anger with the aim of overthrowing the ruling Communist Party.

Reuters - February 14, 2017