SUEZ, Egypt (AP) — Tugboats and a specialized suction dredger worked Friday 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. It got stuck in a single-lane stretch of the canal, about six kilometers (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 237 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 on a lake mid-canal, said Leth Agencies, which provides services for the canal.

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 remained en route to the waterway over the next two weeks.

Some ships now may be changing course to avoid using the Suez Canal. 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 Friday from MarineTraffic.com.

Internationally, many are getting ready for the effect that the shipping pause will have on supply chains that rely on precise deliveries of goods. Singapore’s Minister of Transport Ong Ye Kung said the country’s port should expect disruptions.

“Should that happen, some draw down on inventories will become necessary,” he said in a Facebook post.

The backlog of vessels could stress European ports and the international supply of containers, already strained by the coronavirus pandemic, according to IHS Markit, a business research group. It said 49 container ships were scheduled to pass through the canal in the seven days following Tuesday, when the Ever Given became lodged.

The delay could also result in hefty insurance claims by companies, according to Marcus Baker, Global Head of Marine & Cargo at the insurance broker Marsh, with a ship like the Ever Given usually covered at between $100 – $200 million.

But as of Friday morning, the vessel remained grounded, Leth Agencies added, as Egyptian authorities prohibited media access to the site. It remains unclear when the route would reopen.

“We certainly hope that the canal will be open, and the accident can be handled properly as soon as possible,” said a spokeswoman for China’s foreign ministry, Hua Chunying.

An Egyptian official at the Suez Canal Authority said those trying to dislodge the vessel wanted to avoid complications that could extend the canal closure. The official spoke on condition of anonymity as he was not authorized to talk to journalists. In a Friday statement, the authority said it welcomed offers of international support to help free the vessel, including one from The United States. It did not specify what kind of assistance was offered.

Satellite and photos distributed by the canal’s authority show Ever Given’s bow touching the eastern wall, while its stern appeared lodged against the western wall.

A team from Boskalis, a Dutch firm specialized in salvaging, started working with the canal authority 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 specialized suction dredger that is able to shift 2,000 cubic meters of material every hour.

The authority said late Thursday that it would need to remove between 15,000 to 20,000 cubic meters (530,000 to 706,000 cubic feet) of sand to reach a depth of 12 to 16 meters (39 to 52 feet). That depth is likely to allow the ship to float freely again, it said.

It wasn’t 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 in a statement that 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 bad weather for the incident.

The Ever Given was involved in an accident in northern Germany in early 2019, when the freighter ran into a small ferry that was moored on the Elbe river in the port city of Hamburg. No passengers were aboard the ferry at the time and there were no injuries, but the collision caused serious damage to the boat.

Hamburg prosecutors opened an investigation of the freighter’s captain and pilot on suspicion of endangering shipping traffic, but shelved it in March 2020 for lack of evidence, spokeswoman Liddy Oechtering told The Associated Press on Friday.

Pilots from Egypt’s Suez Canal Authority board transiting ships to guide them through the narrow canal, but the the ship’s captain retains ultimate authority over the vessel, according to shipping experts.

Oechtering also could not say what the investigation had determined the cause of the 2019 crash was, but officials at the time suggested that strong winds may have blown the slow moving freighter into the ferry.