Rescuers are trying to reach remote villages in Mozambique where a powerful cyclone caused widespread devastation.
There are fears thousands of people may be trapped as heavy rain and high winds risk more flooding and landslides.
Cyclone Kenneth struck on Thursday with winds of 220km/h (140mph), barely a month after Cyclone Idai killed more than 900 people across three countries.
Thousands of homes have been flattened, power lines damaged and low-lying areas deluged by the storm.
UN weather experts say it is unprecedented for two cyclones of such intensity to hit Mozambique in the same season.
The World Meteorological Organisation (WMO) also said that no previous records show a cyclone striking the region as far north as Kenneth.
It said a fact-finding mission would examine the “impact of climate change and sea-level rise on Mozambique’s resilience” to extreme weather.
Amnesty International’s Secretary-General Kumi Naidoo said the two storms were “exactly what climate scientists warned would happen if we continue to warm our planet beyond its limits”.
“There is one inescapable and burning injustice we cannot stress enough,” he said, adding: “The people of Mozambique are paying the price for dangerous climate change when they have done next to nothing to cause this crisis.”
The UN’s World Food Programme said it was working on an “emergency preparedness plan” with the Mozambican government and other humanitarian groups.
