(Reuters) – The United ‌States on Tuesday re-imposed sanctions on Iranian oil, as a U.S. official warned that Iran’s attacks on vessels in the Strait of Hormuz were “wholly unacceptable” and would be met with consequences.

Oil prices were up more than 5% following the announcement. The U.S. Treasury had ​authorized last month Iran oil sales until August 21, as part of the fragile agreement ​between Tehran and Washington. Tuesday’s revocation cuts that wind-down period to an end date ⁠of July 17.

The U.S. move came after three tankers reported being struck by unknown projectiles in and ​near the Strait of Hormuz in recent days, the British navy-affiliated agency UKMTO said in a report. ​There was no immediate comment from Tehran, or any claim of responsibility.