The attack targeted Liberian-flagged oil tanker Mercer Street north-east of the Omani island of Masirah. The location is more than 185 miles south-east of Oman's capital, Muscat.
Israeli officials did not immediately acknowledge the attack, but it comes amid heightened tensions between the country and Iran as negotiations remain stalled over Tehran's nuclear deal with world powers.
Other Israeli-linked ships have been targeted in recent months as well amid a shadow war between the two nations, with Israeli officials blaming the Islamic Republic for the assaults.
Meanwhile, Israel has been suspected in a series of major attacks targeting Iran's nuclear programme.
London-based Zodiac Maritime, part of Israeli billionaire Eyal Ofer's Zodiac Group, issued a statement saying the ship was the Liberian-flagged oil tanker Mercer Street and was Japanese owned. The British Defence Ministry had earlier misidentified the ship's owners.
Zodiac Maritime described the attack on Thursday night as "piracy", without elaborating further.
It later said the attack killed two crew members, one from the United Kingdom and another from Romania.
It said the company was "not aware of harm to any other personnel".