OSLO (Reuters) - A video provided by the United States is not sufficient to prove that Iran is behind the attacks on oil tankers in the Gulf of Oman, German Foreign Minister Heiko Maas said on Friday.

Washington released a video that it said showed Iran’s Revolutionary Guards were behind Thursday’s attacks on the Norwegian-owned Front Altair and the Japanese-owned Kokuka Courageous near the Strait of Hormuz shipping chokepoint.

“The video is not enough. We can understand what is being shown, sure, but to make a final assessment, this is not enough for me,” Maas told reporters during a visit to Oslo.