The UK Maritime Trade Operations Center said it received a report of “suspicious activity” 75 nautical miles east of Aden in Yemen.

Based on this alert, whose source has been stated as “military officials,” an oil tanker moving west reported that a small boat had been tailing it and attempted to stop the tanker.

The incident was reported on Thursday, 26 Shahrivar, at 17:29 Iran time. The UK Maritime Trade Operations Center said authorities are investigating it.

The center asked passing vessels to transit through the area with caution and to report any suspicious activity.