Peruvian authorities launched a probe into an oil spill caused by waves triggered by the Pacific tsunami that resulted from a volcanic eruption thousands of miles away, which led to an environmental catastrophe and affected the livelihoods of fishermen.

Prosecutors opened an investigation on Tuesday into a unit of Spanish energy firm Repsol after an oil spill at a local refinery blamed on the unusually large waves from the weekend volcanic eruption and tsunami in Tonga 10,000 kilometers (6,213 miles) away. The eruption caused waves that crossed the Pacific. In Peru, two people drowned off a beach and there were reports of minor damage from New Zealand to Santa Cruz, California.

The South American country's environmental minister gave the La Pampilla refinery, the largest in Peru, two days to identify the critical points of the spill and to collect within 10 days the oil that has spread over wide swathes of the coastline.

A black mass of crude oil could be seen in the water extending some three kilometers along the shoreline and affecting the beaches of three coastal districts, causing maritime contamination and killing birds and ocean microorganisms.

"This is worrying because it is very difficult to remedy," the Minister of the Environment, Ruben Ramirez, said at a press conference. Fines could reach up to $33 million if responsibility for environmental damage were proven, Ramirez was quoted as saying by Reuters.

An undersea volcano near Tonga erupted on Saturday, prompting tsunami warnings and evacuation orders in Japan and causing huge waves on several islands and regions in the South Pacific.

Ramírez had said on Monday that the oil spill had occurred after a ship had been rocked by unusually large waves as it had been unloading crude oil to the La Pampilla Refinery, owned by Repsol. Authorities estimate 6,000 barrels of oil were spilled in the area rich in marine biodiversity, he said.

The National Institute of Civil Defense stated that they already have the spill under control.

The Pampilla Refinery, which said on Sunday there had been "limited spill," said in a statement on Tuesday that it has deployed containment barriers covering the affected areas and that the crude was being collected according to protocol.

"Work is being done to return the coastal area to its original state. More than 200 people divided into crews with specialized equipment are carrying out remediation work on Cavero, Bahía Blanca and Santa Rosa beaches," it said.

Dozens of fishermen gathered in front of the facility in the Callao province near the Peruvian capital of Lima. Under the eyes of the police, the fishermen carried a large Peruvian flag, fishing nets and signs that read "no to ecological crime," "economically affected families" and "Repsol killer of marine fauna." They demanded to speak with company representatives, but no executive approached them.

The company did not immediately return an email from the Associated Press (AP) seeking comment.

"There is a massacre of all the hydrobiological biodiversity," said Roberto Espinoza, leader of the local fishermen. "In the midst of a pandemic, having the sea that feeds us, for not having a contingency plan, they have just destroyed a base of biodiversity."

On Tuesday, northwest of the facility, on Cavero beach, the waves covered the sand with a shiny black liquid, along with small dead crustaceans. Fifty workers from companies that work for Repsol inside the refinery removed the oil-stained sand with shovels and piled it up on a small promontory.

Juan Carlos Riveros, biologist and scientific director in Peru of Oceana – an organization dedicated to protecting the world’s oceans – said that the species most affected by the spill include guano birds, seagulls, terns, tendrils, sea lions and dolphins.

"The spill also affects the main source of work for artisanal fishermen, since access to their traditional fishing areas is restricted or the target species become contaminated or die," Riveros said. "In the short term, mistrust is generated about the quality and the consumption of fishing is discouraged, with which prices fall and income is reduced."

Peru’s environmental assessment and enforcement agency estimates that some 18,000 square meters (193,750 square feet) of beach on Peru’s Pacific coast have been affected by the spill.

In a statement, the Peruvian agency said Repsol "has not adopted immediate measures in order to prevent cumulative or more serious damage that affects the soil, water, flora, fauna and hydrobiological resources." An AP reporter on Monday observed workers dressed in white suits collecting the spilled oil with plastic bottles cut in half.

José Llacuachaqui, another local fisherman leader who was watching the cleanup, said the workers were only collecting the oil that reached the sand, but not the crude that was in the seawater.

"That is preying, killing, all the eggs, all the marine species," he said.