An oil spill caused by a ruptured pipeline in Ecuador's Amazon region leaked almost 6,300 barrels into an environmental reserve, according to information provided Wednesday by the company that owns the conduit.

The firm OCP said it had "collected and reinjected 5,300 barrels of crude into the system" since the accident on Friday when heavy rains caused a boulder to fall on the pipeline in a mountainous region.

OCP said the recovered oil amounted to 84 percent of the total that leaked, which would mean around 6,300 barrels.

The oil was collected in large basins deployed as an emergency measure when there is a leak.

OCP president Jorge Vugdelija said in a statement that the company was using people and machines to "collect traces of crude found in the river."

Around 21,000 square meters of the Cayambe-Coca nature reserve has been affected by the leak.

Crude flowed into the Coca river, one of the largest in Ecuador's part of the Amazon and which serves as a water source for many riverbank communities, including indigenous ones.

"We demand to know... what will be the process of delivering water and food to the communities. It's clear that the river water cannot be used or drunk," the National Confederation of Indigenous Nationalities of the Ecuadoran Amazon said on Twitter.

The Cayambe-Coca national park is 4,000 square kilometers (1,544 square miles) of mountains and rainforest in the Amazon basin sitting between 600 and 5,790 meters (1,970 to 19,000 feet) above sea level.

Heavy rains at the end of last week caused landslides and rock falls in the area of Piedra Fina, where the pipeline lies, in the eastern Napo province.

The 485-kilometer-long pipeline straddles four provinces all the way to the Pacific coast in the west, transporting 160,000 barrels of oil a day from wells in the jungle.

In May 2020 a mudslide damaged pipelines in the same area, resulting in 15,000 barrels of oil polluting three Amazon basin rivers, affecting several riverside communities.

Crude petroleum is Ecuador's biggest export product. Between January and November 2021, the country extracted 494,000 barrels per day.

The oil leak is the second to mar South American ecosystems in two weeks, after nearly 12,000 barrels of crude spilled into the sea off Peru on January 15.