A LIBERIAN-FLAGGED oil tanker in the Red Sea came under attack three times on Tuesday, including an assault using a bomb-carrying drone boat, likely the latest in a campaign by Yemen's Houthi rebels over the Israel-Hamas war, officials said.

The attacks come as the rebels' main sponsor, Iran, weighs possible retaliation against Israel over the assassination of Hamas official Ismail Haniyeh last month in Tehran, Iran's capital, which has renewed fears of a wider regional war in the Middle East.

Already, the Houthi assaults have disrupted the US$1 trillion annual flow of goods through the maritime route crucial to trade among Asia, Europe and the Middle East, while also sparking the most intense combat for the US Navy since World War II.

The Greek-managed Delta Atlantica was first attacked when two explosives detonated near it, according to the Joint Maritime Information Centre, a multinational force overseen by the US Navy, reports ABC News.

A small ship "flashing lights" at the vessel had come close to the loaded tanker bound for Greece during the incident, the centre said.

A small ship later flashed lights at the Delta Atlantica before another explosion near it, the centre said.

The third attack happened hours later on Tuesday, some 180 kilometres (110 miles) northwest of the Houthi-held port city Hodeida, prompting an armed security force aboard the tanker to open fire.

"The vessel was approached by an uncrewed surface vessel on the starboard side. The USV collided with the vessel but did not detonate," the centre said. "Subsequently, the armed security team disabled the USV via small arms fire."

Another vessel, identified by the centre as a Panama-flagged crude oil tanker called On Phoenix, also saw an explosion off its side on Tuesday, but similarly sustained no damage, the centre said.

The Houthis have so far not claimed responsibility for the assaults, though sometimes they wait days to do so, and other times they have claimed attacks that appear not to have happened.

The Houthis have targeted more than 70 vessels with missiles and drones since the start of the war in Gaza in October. They have seized one vessel and sunk two in the campaign that has killed four sailors.

Other missiles and drones have been either intercepted by a US-led coalition in the Red Sea or failed to reach their targets.