(Reuters) - Protests were held at several places along Vietnam’s coast on Thursday, a year after the country’s worst environmental disaster was caused by a spill from a steel mill, activists said.

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Sea life began washing up on April 6, 2016 near a steel plant being developed by Taiwan’s Formosa Plastics Corp. Within weeks, more than 200 km (125 miles) of coast had been contaminated.

After months of rallies and an outpouring of anger not seen in four decades of Communist Party rule, Formosa agreed to pay $500 million in compensation.

On Thursday, people in Nghe An, Ha Tinh and Quang Binh provinces, led by church groups, held demonstrations on land and aboard boats in a show of anger towards Formosa and the government for their handling of the incident, activists said.

Pictures and videos posted on Facebook showed people carrying banners saying “Who has brought Formosa here to poison Vietnam?”.

Others said “Government takes money, people take disaster”.

In one area, fishermen took boats to sea to hold a protest without risking suppression by the local authority, activist Paul Tran Minh Nhat said.

But none of the groups protesting on Thursday had faced any intervention from the police, he said.

Nghe An and Ha Tinh provincial authorities were not immediately reachable for comment.

The government said on Thursday it was prosecuting one man accused of agitating for destruction of Formosa’s facilities, but that did not appear related to the latest protests.

The demonstrations came one day after Vietnam’s environment ministry said Formosa’s steel mill has met environment ministry conditions to start test runs after addressing 52 out of 53 violations, sparking worries among activists.