A video released by the U.S. Navy Friday morning appears to show an Iranian Revolutionary Guard patrol vessel removing an unexploded limpet mine from a commercial fuel tanker struck in an attack in the Gulf of Oman Thursday. The Associated Press reports the actions suggests the Islamic Republic “sought to remove evidence of its involvement from the scene.” On Thursday, the U.S. Secretary of State Mike Pompeo blamed Iran for the attack on the Norwegian and Japanese oil tankers.

Iran on Friday firmly denied involvement, accusing the U.S. of waging an “Iranophobic campaign.” “Iran categorically rejects the U.S.’s unfounded claim with regard to 13 June oil tanker incidents and condemns it in the strongest possible terms,” its statement said. The U.S. “immediately jumped to make allegations against Iran—[without] a shred of factual or circumstantial evidence” and was “sabotaging diplomacy,” Iranian Foreign Minister Javad Zarif tweeted. The U.S. Navy also responded to the explosions on the oil tankers on Thursday, evacuating several of the mariners.