Two missiles hit an Iranian oil tanker 60 miles off the coast of Saudi Arabia on Friday, causing a brief oil leak and increase in oil prices, as well as increased tensions in the Middle East.

The oil from the Sabiti, owned by the National Iranian Oil Company, leaked into the Red Sea near the Saudi port city of Jeddah, according to Iranian state media.

“This latest incident, if confirmed to be an act of aggression, is highly likely to be part of the wider narrative of deteriorating relations between Saudi and the U.S. and Iran,” private maritime security firm Dryad Maritime told the Associated Press. “It is likely that the region, having been stable for the last month, will face another period of increasing maritime threats, as the Iranian and Saudi geopolitical stand-off continues.”

The tanker was carrying about 1 million barrels of oil when the attack occurred, according to an analysis from data firm Refinitiv.

The Iranians have yet to say who was responsible.

The U.S. Navy is aware of the attack.

“We are aware of the reports, but we don’t have any further information,” a spokesperson for the Navy’s Fifth Fleet told Reuters.