Dutch military helps clean oil along beaches in Caribbean island of Bonaire

The Dutch flag flies on the stern of a ship as it passes a container terminal, rear, in the harbor of Rotterdam, Netherlands, Tuesday, Sept. 11, 2018. (AP Photo/Peter Dejong)

Armed forces from the Netherlands have been deployed to help clean up oil affecting beaches in the Dutch Caribbean island of Bonaire originating from an offshore spill blamed on an overturned barge hundreds of miles away.

The military cleaned up several beaches on the island that remain closed to the public, officials said Thursday.

"The situation seems to be under control," acting Lt. Gov. Reynolds Oleana said. "It remains to be seen what will happen in the coming days."

Environmental officials said they can start assessing the damage once the polluted areas have been cleaned.

The spill occurred last month near Trinidad and Tobago and prompted officials there to declare a national emergency.

The government of the twin-island nation said earlier this week that a minimum of 420,000 gallons (1.6 million liters) of oil mixed with water has been vacuumed from nearby waters. They warn the number is likely larger since it does not include "a substantial amount" of oil that traveled across the Caribbean Sea or that was picked up with sand and sargassum.

A preliminary investigation has found that the overturned barge had departed from Panama and was being tugged to nearby Guyana when it began to sink.

The owner of the barge has not been found.

Officials in Tobago have warned that the spill would take up to eight months to be fully cleaned, and that remediation efforts including repopulating ecosystems would take up to three years.