Tugboats and dredgers were working yesterday to free a giant container ship blocking Egypt's Suez Canal for a fourth day, forcing companies to re-route services from the vital shipping lane around Africa.

The MV Ever Given, which is longer than four football fields, has been wedged diagonally across the entire canal since Tuesday, when social media users began posting about it.

The blockage has caused huge traffic jams for dozens of ships and major delays in the delivery of oil and other products.

An official from Shoei Kisen Kaisha, the Japanese company that owns the ship, told AFP yesterday that crews were working to refloat it.

"Tug boats and dredgers are being used to crush rocks" in efforts to dislodge the boat, she told AFP, adding that the company did not have information on the exact status of damage to the vessel.

Global shipping giant Maersk and Germany's Hapag-Lloyd have both said they are looking into re-routing around the southern tip of Africa.

"With the Suez Canal set to remain blocked for at least another day or two, shipping companies are being forced to confront the spectre of taking the far longer route around the Cape of Good Hope to get to Europe or the east coast of North America," said Lloyd's List, a shipping data and news company.

"The first container ship to do this is Evergreen's Ever Greet... a sistership to Ever Given," it said in a statement.

The Suez Canal drastically shortens travel between Asia and Europe.

The Singapore-Rotterdam route, for example, is 6,000 kilometres (3,700 miles) and up to two weeks shorter via the canal than going around Africa's Cape of Good Hope.

The stranded Ever Given is holding up an estimated $9.6bn (£7bn) of goods each day, according to shipping data.

Data from shipping expert Lloyd's List values the canal's westbound traffic at roughly $5.1bn a day, and eastbound daily traffic at around $4.5bn, reports BBC.

Egypt's Suez Canal Authority has said between 15,000 and 20,000 cubic metres of sand would have to be removed in order to reach a depth of 12-16 metres and refloat the ship.

Egyptian President Abdel Fattah al-Sisi's seaports adviser, Mohab Mamish, told AFP late Thursday that "maritime navigation will resume again within 48-72 hours, maximum".