The unnamed vessel was approached by gunmen in four boats, according to the state-run Kuna news agency, citing Kuwait Oil Tanker Co (KOTC) CEO Sheikh Talal Al-Sabah.
AIS data shows KOTC's 46,500-dwt products/chemical carrier Burgan (built 2014) in the area on 8 February, with an estimated date of arrival in Djibouti on Monday.
The tanker has berthed with the crew unharmed, Kuna said.