An oil spill is sloshing tarry ooze onto beaches in the state of Carabobo along Venezuela's western coastline, several environmental groups said on Wednesday.

The spill was first detected on Tuesday, Yohan Flores, a regional director of the Azul Ambientalistas NGO, told AFP.

"A large part of the beaches of Puerto Cabello are affected," he said, referring to the country's largest port 210 kilometers (130 miles) west of the capital Caracas.

State oil giant PDVSA has not addressed the spill even as NGOs such as the Caribe Sur Foundation say it originated at a waste lagoon near the El Palito refinery, one of the most important in Venezuela.

A brief report from the National System for Risk Management noted a "spill of hydrocarbons from the waste lagoon" without offering more details.

"A large part of the beaches of Puerto Cabello (in Carabobo state) are affected," said Flores, adding that marine fauna may also be affected.

Teams from PDVSA, volunteers and fishermen all were seen working on cleanup.

The National Organization for Rescue and Maritime Safety of Venezuela's Aquatic Spaces (ONSA) called for "environmental contingency" action.

The last oil spill recorded in the area was in July 2020, when waste from the refinery also flowed into the sea.

That accident contaminated the Morrocoy National Park, a tourist area with a score of islets with white sand beaches.

Fishermen near Puerto Cabello said that they will not be able to fish for the next two months.

Venezuela, which has one of the world's largest oil reserves, saw its production fall from 3 million barrels per day more than a decade ago to 850,000 barrels per day now, with production expected to surpass 1 million barrels later next year.