Tugboats and a specialised suction dredger are working to dislodge a giant container ship that has been stuck sideways in Egypt’s Suez Canal for the past three days, blocking a crucial waterway for global shipping.

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

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

The ship, owned by the Japanese firm Shoei Kisen KK, has blocked traffic in the canal, causing headaches for global trade.

Around 10% of world trade flows through the canal, which is particularly crucial for the transport of oil. The closure also could affect oil and gas shipments to Europe from the Middle East.

At least 150 ships were waiting for the Ever Given to be cleared, including vessels near Port Said on the Mediterranean Sea, Port Suez on the Red Sea, and those already stuck in the canal system on Egypt’s Great Bitter Lake, according to Leth Agencies, which provides services for the canal.

As of Friday morning, the vessel remains grounded, Leth Agencies added.

It remains unclear when the route will reopen.

An Egyptian official at the Suez Canal Authority described the work as complex and said those trying to dislodge the vessel wanted to avoid complications that could extend the canal closure.

The Ever Given’s bow was touching the eastern wall, while its stern appeared lodged against the western wall.

A team from Boskalis, a Dutch salvage firm, started working with the canal authority on Thursday.

The rescue efforts have focused on dredging to remove sand and mud from around the port side of the vessel’s bow.

The Suez Canal Authority, which operates the waterway, deployed tugboats and a specialised suction dredger that is able to shift around 2,000 cubic metres (70,629 cubic feet) of material every hour.

The Suez Canal Authority said it would need to remove between 15,000 to 20,000 cubic metres (530,000 to 706,000 cubic feet) of sand to reach a depth of 12-16 metres (39-52ft). That depth is likely to allow the ship to float freely again, it said.

It was not immediately clear what caused the Ever Given to become wedged on Tuesday. GAC, a global shipping and logistics company, said the ship had experienced a blackout, without elaborating.

Evergreen Marine Corp, a major Taiwan-based shipping company that operates the ship, said the Ever Given had been overcome by strong winds as it entered the canal from the Red Sea, but that none of its containers had sunk.

The Suez Canal Authority also blamed the incident on bad weather.

Using data from Automatic Identification System trackers on ships at sea, data firm Refinitiv shared an analysis with the AP showing that over 300 ships remain en route to the waterway over the next two weeks.

Some vessels could still change course, but the crush of ships listing the Suez Canal as their destination shows that an even-greater backlog looms for shippers already under pressure amid the coronavirus pandemic.