At least 11 people have died after sudden rains caused flooding in the Mauritian capital Port Louis on Saturday, officials have said.
At least eight of the victims were caught in underground areas as the flood waters rose rapidly. Another died of a heart attack.
The island's metereologists said 152mm (6in) of rain fell in less than an hour, 70mm less than the March average.
Prime Minister Navin Rangoolam declared 1 April a day of mourning.
Speaking on national radio, he said Mauritius was suffering badly from the effects of climate change.
The floods caused chaos in the city, with a huge traffic jam paralysing its centre, L'Express de Maurice newspaper reported.
A BBC reporter in the city says the bodies of six people were recovered from a pedestrian subway and another two from an underground car park.
Resident Ameeksha Dichand told the BBC she had been unable to go outside because it was raining so heavily, though people did venture out on Sunday to inspect the damage.
"The roads are blocked and there is mud everywhere. Trees have fallen all over the place," she said.
"If people couldn't rely on their neighbours so much to help them, then we would have lost more lives. I am so angry at the authorities."
More rain was expected on Sunday, and people were advised to stay at home.