Saudi Arabia has reportedly banned Iranian oil tankers from entering its waters, in an effort to slow Iran's oil exports. A Financial Times report earlier this week said Iranian vessels are restricted from entering Saudi ports.

And Bahrain, a Saudi ally, has issued similar restrictions. The paper reports that Iran has also been denied access to insurance, financing and key oil storage facilities owned by Saudi Arabia. Saudi Arabia and other OPEC members are urging Iran to freeze oil output and exports to help shore up prices.