DAKAR, Senegal (AP) — Congo canceled an auction for 27 sites earmarked for oil exploration, its government said, citing late submissions and a lack of competition.

The auction for the sites, known as oil blocks, was initially launched two years ago but was called off after it failed to achieve the expected success and a new auction will be held, said oil minister Aimé Sakombi Molendo in a statement. He gave no details about timing or the number of blocks to be put up for bidding in future.

The 27 oil blocks canceled auction hold an estimated 22 billion barrels.

Congo, a mineral-rich nation in central Africa, is thought to have significant oil reserves but drilling has so far been confined to a small territory on the Atlantic Ocean and offshore.

That was expected to change with the auction.

Environmental agencies have sounded the alarm since Congo launched the auction in July 2022, saying that auctioning more land to drill would have consequences both in Congo and abroad.

Congo is home to most of the Congo Basin rainforest, the world’s second-biggest, and most of the world’s largest tropical peatland, made up of partially decomposed wetland plant material.

Together, both capture huge amounts of carbon dioxide — about 1.5 billion tons a year, or about 3% of global emissions. More than a dozen of the plots up for auction overlap with protected areas in peatlands and rainforests, including the Virunga National Park, which is home to some of the world’s rarest gorillas.