More than 1,000 people are feared dead in a devastating cyclone that hit Mozambique on Friday, the country’s president has said.

Filipe Nyusi told Mozambican radio he had seen “many bodies” floating in the overflowing Pungwe and Busi rivers. “It appears that we can register more than 1,000 deaths,” he said, adding that more than 100,000 people were at risk because of severe flooding.

At least 215 people have been confirmed dead and hundreds are missing across Mozambique, Malawi and Zimbabwe from Tropical Cyclone Idai, according to government agencies and the Red Cross, which said 1.5 million people had been affected.

A more precise death toll and the true scale of the damage is not likely to be known soon, as many areas are cut off.

“I think this is the biggest natural disaster Mozambique has ever faced. Everything is destroyed,” Celso Correia, the environment minister, said. “Our priority now is to save human lives.”

Residents of the devastated port city of Beira, where the Pungwe and Busi rivers flow into the sea, have had no communications since Idai hit. Many families have been frantically trying to get information about their relatives, but with no phones or internet access, no electricity and great chunks of the main road into Beira washed away and blocked by flooding, all they can do is wait.

Despite the difficulty of getting much-needed supplies, equipment, rescue teams and other people into the area, some humanitarian organisations managed to fly in and begin taking stock of the damage.

“The situation is terrible. The scale of devastation is enormous. It seems that 90 per cent of the area is completely destroyed,” said Jamie LeSueur of the Red Cross. “We are also hearing that the situation outside the city could be even worse. Yesterday, a large dam burst and cut off the last road to the city.”