The Indian Ocean island of Mauritius has declared a "state of environmental emergency" after a Japanese-owned ship that ran aground offshore days ago began spilling tons of fuel.

The country's Prime Minister Pravind Jugnauth announced the development late Friday as satellite images showed a dark slick spreading in the turquoise waters near environmental areas that the government called "very sensitive."

Mauritius said the ship was carrying nearly 4,000 tons of fuel and cracks have appeared in its hull. It ran aground July 25 and the National Coast Guard received no distress call in recent days.

Jugnauth said his government had appealed to France for help, saying the spill "represents a danger" for the country of some 1.3 million people that relies heavily on tourism and has been hit hard by the effects of the coronavirus pandemic.

"Our country doesn't have the skills and expertise to refloat stranded ships," Jugnauth said. Bad weather has made it impossible to act, and "I worry what could happen Sunday when the weather deteriorates," he added.

French President Emmanuel Macron pledged on Saturday to send teams and equipment to help Mauritius deal with the spill that environmentalists fear could be a major ecological disaster.

"When biodiversity is in peril, there is urgency to act," Macron tweeted Saturday. "France is there. Alongside the people of Mauritius. You can count on our support dear Jugnauth.”

The French island of Reunion is the closest neighbor to Mauritius. A separate French statement from Reunion said a military transport aircraft would carry pollution control equipment to Mauritius and a navy vessel with additional material would set sail for the island nation.

"We are in a situation of environmental crisis," the environment minister of Mauritius, Kavy Ramano said earlier.

After the cracks in the hull were detected, a salvage team that had been working on the ship was evacuated, Ramano said Thursday. Some 400 sea booms were deployed in an effort to contain the spill.

Tons of diesel and oil are now leaking into the water, environmental group Greenpeace Africa's climate and energy manager Happy Khambule said in a statement.

The ship's owners were listed as a Japanese company. 

A statement by the company said that "due to the bad weather and constant pounding over the past few days, the starboard side bunker tank of the vessel has been breached and an amount of fuel oil has escaped into the sea.”

The company would take every effort with partner agencies and contractors to protect the marine environment and prevent further pollution, it added.

A government environmental outlook released nearly a decade ago said Mauritius had a National Oil Spill Contingency Plan but equipment on hand was "adequate to deal with oil spills of less than 10 metric tonnes."

In case of major spills, it said, assistance could be obtained from other Indian Ocean countries or from international oil spill response organizations.

(With input from AP and AFP)