An oil tanker is seen after it was attacked at the Gulf of Oman, June 13, 2019. The Iranian news agency IRNA reported on Thursday that the Front Altair, an oil tanker damaged in an attack in the Gulf of Oman, had sunk. Earlier reports had said the tanker was carrying 75,000 tonnes of naphtha, a flammable liquid hydrocarbon. ISNA/Handout via REUTERS

An oil tanker is seen after it was attacked at the Gulf of Oman, June 13, 2019. Iranian search and rescue teams picked up 44 sailors from the Front Altair and another damaged tanker, the Islamic Republic News Agency (IRNA) reported on Thursday, citing an unnamed informed source. The sailors were taken to the Iranian port of Jask, IRNA reported. ISNA/Handout via REUTERS

An oil tanker is seen after it was attacked at the Gulf of Oman, June 13, 2019. Twenty-three crew on the Front Altair, a Marshall Islands-flagged tanker heading from Qatar to Taiwan, abandoned ship when a fire broke out approximately 25 miles from Jask. They were picked up by a passing ship and handed over to an Iranian rescue vessel, IRNA reported. ISNA/Handout via REUTERS

An oil tanker is seen after it was attacked at the Gulf of Oman, June 13, 2019. The second tanker was a Panama-flagged ship heading from a port in Saudi Arabia towards Singapore when a fire broke out approximately 28 miles from Jask. Twenty-one crew abandoned that ship and were picked up by Iranian search and rescue teams, IRNA reported. ISNA/Handout via REUTERS

A handout photo made available by the Norwegian shipowner Frontline of the crude oil tanker Front Altair during the firefighting of the fire onboard the ship in the Gulf of Oman, June 13, 2019. The Iranian news agency IRNA reported on Thursday that the Front Altair, an oil tanker damaged in an attack in the Gulf of Oman, had sunk. Earlier reports had said the tanker was carrying 75,000 tonnes of naphtha, a flammable liquid hydrocarbon. Frontline/NTB Scanpix/via REUTERS

A handout photo made available by the Norwegian shipowner Frontline of the crude oil tanker Front Altair after the fire onboard the ship in the Gulf of Oman, June 13, 2019. The Iranian news agency IRNA reported on Thursday that the Front Altair, an oil tanker damaged in an attack in the Gulf of Oman, had sunk. Earlier reports had said the tanker was carrying 75,000 tonnes of naphtha, a flammable liquid hydrocarbon. Frontline/NTB Scanpix/via REUTERS