A 400m-long ship likened to a "beached whale" blocking the Suez Canal could take weeks to move, authorities have warned.
The Ever Given, a three-year-old 220,000 tonne vessel, first became wedged in the largest shipping lane on the planet on Tuesday.
Five tugs are working to drag the vessel to deeper water, according to ship-tracking data.
New photos released today show tug boats working and dredgers trying to clear sand and mud from around the stuck ship.
Peter Berdowski, CEO of Dutch company Boskalis, which is trying to free the ship, said it was too early to say how long the job might take.
"We can't exclude it might take weeks, depending on the situation," Mr Berdowski told the Dutch television programme Nieuwsuur.
He said the ship's bow and stern had been lifted up against either side of the canal.
Mr Berdowski added: "It is like an enormous beached whale. It's an enormous weight on the sand.
"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."
The ship 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 (SCA) said in a statement.
Efforts to dislodge the 1,312 foot long container, which has choked traffic along the Suez Canal, resumed at high tide on Thursday.
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.
Bernhard Schulte Shipmanagement (BSM), the technical manager of Ever Given, said dredgers were working to clear sand and mud from around the vessel to free her while tugboats in conjunction with Ever Given's winches are working to shift it.
Marine services firm GAC issued a note to clients overnight saying efforts to free the vessel using tug boats continued, but that wind conditions 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 seen for years.
Roughly 30 per cent of the world's shipping container volume transits through the 193 km (120 miles) Suez Canal daily, and about 12 per cent of total global trade of all goods.
Shipping experts say that if the blockage is not likely to be cleared within the next 24 to 48 hours, some shipping firms may be forced to re-route vessels around the southern tip of Africa.
This would add roughly a week to the journey.
But the chairman of the Suez Canal Authority told media that despite the blockage some cargo was able to move south and that efforts to dislodge Ever Given would continue.
