A giant container ship remained stuck sideways in Egypt’s Suez Canal for a fifth day Saturday, as authorities prepared to make new attempts to free the vessel and reopen a crucial east-west waterway for global shipping.

The Ever Given, a Panama-flagged ship that carries cargo between Asia and Europe, ran aground Tuesday in the narrow canal that runs between Africa and the Sinai Peninsula.

The massive vessel got stuck in a single-lane stretch of the canal, about six kilometres (3.7 miles) north of the southern entrance, near the city of Suez.

In a press conference Saturday in Suez, the head of the canal authority, Lt. Gen. Osama Rabei, told reporters that they could not lay out a set timetable for when the ship might be dislodged. He said he remained hopeful that a dredging operation could free the ship without having to resort to lighten it by removing its cargo.

“It’s difficult to deal with easily,” he said.

A maritime traffic jam grew to around 321 vessels near Port Said on the Mediterranean Sea, Port Suez on the Red Sea and in the canal system on Egypt’s Great Bitter Lake, according to Rabei.

Peter Berdowski, CEO of Boskalis, the salvage firm hired to extract the Ever Given, said the company hoped to pull the container ship free within days using a combination of heavy tugboats, dredging and high tides.

He told the Dutch current affairs show Nieuwsuur on Friday night that the front of the ship is stuck in sandy clay, but the rear “has not been completely pushed into the clay and that is positive because you can use the rear end to pull it free.”

Berdowski said two large tugboats were on their way to the canal and are expected to arrive over the weekend. He said the company aims to harness the power of the tugs, dredging and tides, which he said are expected to be up to 50 centimetres (20 inches) higher Saturday.

“The combination of the (tug) boats we will have there, more ground dredged away and the high tide, we hope that will be enough to get the ship free somewhere early next week,” he said.

If that doesn’t work, the company will remove hundreds of containers from the front of the ship to lighten it, effectively lifting the ship to make it easier to pull free, Berdowski said.

A crane was already on its way that can lift the containers off the ship, he said.

The salvage mission was turning its focus to the ship’s lodged bow, after some progress was made towards freeing the ship’s stern, the canal service provider Leth Agencies said Saturday.

Egypt Prime Minister Mustafa Madbouly called the ship’s predicament “a very extraordinary incident,” in his first public comments on the blockage.

Shoei Kisen, the company that owns the giant container ship said the company was considering removing containers to lighten the vessel if other refloating efforts fail.

The White House said it has offered to help Egypt reopen the canal. “We have equipment and capacity that most countries don’t have and we’re seeing what we can do and what help we can be,” President Joe Biden told reporters Friday.

An initial investigation showed the vessel ran aground due to strong winds and ruled out mechanical or engine failure, the company and the canal authority said. GAC, a global shipping and logistics company, had previously said the ship had experienced a power blackout, but it did not elaborate.

Rabei, the canal authority head, said the winds were one of the factors but “not the only cause” of the incident. He said an investigation into the cause of the grounding was ongoing but did not rule out human or technical error.

Some vessels began changing course and dozens of ships were still en route to the waterway, according to the data firm Refinitiv.

A prolonged closure of the crucial waterway would cause delays in the global shipment chain. Some 19,000 vessels passed through the canal last year, according to official figures. About 10% of world trade flows through the canal. The closure could affect oil and gas shipments to Europe from the Middle East.

It remained unclear how long the blockage would last. Even after reopening the canal that links factories in Asia to consumers in Europe, the waiting containers are likely to arrive at busy ports, forcing them to face additional delays before offloading.

Apparently anticipating long delays, the owners of the stuck vessel diverted a sister ship, the Ever Greet, on a course around Africa instead, according to satellite data.

Others are following suit. The liquid natural gas carrier Pan Americas changed course in the mid-Atlantic, now aiming south to go around the southern tip of Africa, according to satellite data from MarineTraffic.com.

Abbotsford News