Health officials in France on Tuesday activated an emergency plan on the Mediterranean island of Corsica as a fourth wave of Covid infections spread across the country.

The government also announced it was reactivating a package of measures designed to support medical staff as they brace for a fresh intake of cases.

More of France's popular coastal areas meanwhile reintroduced the compulsory wearing of masks in a bid to stem the incoming coronavirus tide.

Health officials on Corsica said they were providing more intensive care beds for Covid patients and mobilising medical staff as hospital occupancy in Bastia, one of the island's two main cities, passed 79 percent.

The news came a day after Guadalupe became the third of France's overseas territory to announce a return to partial lockdown because of a "catastrophic" surge in Covid cases there.

An overnight curfew and some daytime restrictions start from Wednesday.

Martinique, another French Caribbean island 190 kilometres (120 miles) to the south, returned to lockdown on Friday, while the island of Reunion entered partial lockdown this weekend.

On Tuesday, Prime Minister Jean Castex chaired a meeting of the interministerial team handling the crisis.

They agreed to use the army to provide more intensive care beds to the overseas territories, his office said.

Health officials on Corsica (pictured July 2021) said they were providing more intensive care beds for Covid patients and mobilising medical staff as hospital occupancy in Bastia, one of the island's two main cities, passed 79 percent
Health officials on Corsica (pictured July 2021) said they were providing more intensive care beds for Covid patients and mobilising medical staff as hospital occupancy in Bastia, one of the island's two main cities, passed 79 percent AFP / Pascal POCHARD-CASABIANCA

The government also announced Tuesday it would reintroduce overtime bonuses for hospital workers, as well as compensation for paid holidays they could not take because of pressure of work.

The situation in Corsica was likely hurt by the traditional surge of departures and arrivals of holidaymakers at the end of July: more than 130,000 people were on the move there last weekend.

Corsica had already reintroduced compulsory mask wearing in the island's main cities in mid-July.

Several coastal resorts around France have also reintroduced compulsory mask wearing less than two months after the authorities lifted the restriction.

In northwest France, Brittany's Finistere area, on Monday ordered people to cover their mouths and noses outdoors after an increase in Covid cases. Masks have been compulsory outdoors in the Morbihan area of Brittany since last week.

Officials in the foothills of the Pyrenees, on the border with Spain, and at Lake Annecy, at the foot of the Alps, have introduced similar measures.

Across France, the Delta variant of the virus is pushing up the number of hospital admissions, public health figures published Tuesday showed.

Patients in intensive care now number 1,331 compared with 978 a week ago, while the deaths of another 57 people over the last 24 hours pushed France's toll past 112,000.

Coronavirus