The marine department said Malaysian ship operators should review and reassess voyage routes and continuously monitor maritime security advisories from international authorities, Bernama reported.

The highest level of operational preparedness should be maintained at all times, the department said.

The warning came after Iran’s Revolutionary Guards are reported to have sent transmissions saying “no ship is allowed to pass the Strait of Hormuz” located between Iran and the Arabian peninsula.

The narrow strait is the world’s most vital oil export route, connecting the biggest Gulf oil producers, such as Saudi Arabia, Iran, Iraq and the United Arab Emirates (UAE), with the Gulf of Oman and the Arabian Sea.

Earlier today, Maersk, the major container shipping company, said it was halting passage through the Strait of Hormuz for safety reasons until further notice.

State media in Oman, which sits on the other side of the strait, said an oil tanker off its coast was targeted and four of its crew hurt. A UK maritime centre said another ship off the UAE’s coast had reported being hit “by an unknown projectile causing a fire”.