Efforts to dislodge a 400m long container vessel that has choked traffic along the Suez Canal have resumed at high tide, with five tugs working to drag the vessel to deeper water.
The Ever Given vessel ran aground diagonally across the single-lane stretch of the southern canal on Tuesday morning after losing the ability to steer amid high winds and a dust storm, the Suez Canal Authority says.
It is now blocking transit in both directions through one of the world's busiest shipping channels for goods, oil, grain and other products linking Asia and Europe.
Peter Berdowski, CEO of Dutch company Boskalis, which is trying to free the ship, said on Thursday it was too early to say how long the job might take.
"We can't exclude it might take weeks, depending on the situation," he told Dutch TV program Nieuwsuur.
He said the ship's bow and stern had been lifted up against either side of the canal.
"It is like an enormous beached whale. It's an enormous weight on the sand," Boskalis said.
"We might have to work with a combination of reducing the weight by removing containers, oil and water from the ship, tug boats and dredging of sand."
Bernhard Schulte Shipmanagement, the technical manager of Ever Given, said dredgers were working to clear sand and mud from around the vessel while tugboats and Ever Given's winches were trying to shift it.
Marine services firm GAC issued a note to clients overnight saying efforts to free the vessel using tug boats continued but winds and the sheer size of the vessel "were hindering the operation".
Ship-tracking software shows five tugs surrounding the Ever Given and three more heading towards it.
The ship's GPS signal shows only minor changes to its position over the past 24 hours, however.
Several dozen vessels, including other large container ships, tankers carrying oil and gas, and bulk vessels hauling grain have backed up at either end of the canal to create one of the worst shipping jams in years.
Roughly 30 per cent of the world's shipping container volume transits through the 193km Suez Canal daily, and about 12 per cent of total global trade of all goods.
Experts say if the blockage is not cleared within the next 48 hours, some firms may be forced to re-route vessels around the southern tip of Africa, which would add roughly a week to the journey.