Following protests by environmental activists who claim its operations in the region violate a treaty limiting mineral development, a Russian research vessel that has been searching for oil and natural gas in the Antarctic arrived in South Africa on Saturday.

Hands off Antarctica” banners were being raised by several members of the environmental movement Extinction Rebellion as the polar explorer ship Akademik Alexander Karpinsky made its scheduled morning arrival in Cape Town.

Earlier this week, several dozen protesters from Greenpeace and Extinction Rebellion demonstrated at the port, saying the ship’s seismic surveys in the Antarctic were a threat to marine life in the area and violated a 1958 international agreement.

A 1998 amendment to the 55-nation Antarctic Treaty, to which both Russia and South Africa are signatories, prohibits all mineral explorations and extractions in the region.

RosGeo, the state-owned Russian exploration company that operates the Akademik Alexander Karpinsky, says it has been conducting research in Russia’s designated part of Antarctica since 1970 to explore for hydrocarbons.

According to RosGeo’s website, the hydrocarbon potential of the designated area is estimated at approximately 70 billion tonnes.

RosGeo did not immediately reply to a request for comment.

According to Cassie Goodman of Extinction Rebellion, by allowing the Russian ship to dock, the South African government contributed to environmental harm.

An inquiry for comment was not immediately answered by the South African Foreign Ministry.

The administration of President Cyril Ramaphosa enjoys cordial ties with Russia. South Africa claims to be objective on the conflict in Ukraine and has abstained from casting a vote on resolutions related to the conflict.

Russian Foreign Minister Sergei Lavrov visited South Africa earlier this week, and from February 17 and February 27, the two nations will undertake a combined military drill on the east coast of the African nation.