The cyclone slammed into the coast on Thursday, killing five people near the southern tourist town of Vilanculos, and although it was downgraded to a tropical storm, it brought pounding rains to a region already struggling to cope with flooding.
Moyane said the storm damaged buildings as it swept through the area on Saturday, bringing downpours that filled the already swollen Buzi river.
"Because of the communication problems we are still looking for people either stranded or injured"
Casmiro Abreu, spokesman for INGC's emergency operation centre
Relief workers are battling to supply food and fresh water to some 140,000 people who have been displaced by flooding in four central provinces
South Africa and the European Union on Saturday both pledged more help for the relief effort.
Casmiro Abreu, a spokesman for the emergency operation centre run by Mozambique's national relief agency INGC, said: "Because of the communication problems we are still looking for people either stranded or injured."
Officials were seeking to help 36,000 people in the area who lost virtually all their possessions.
Abreu said: "We are currently distributing a little amount of food which we have and building toilets."
Tourists were airlifted on Friday from hotels in the Bazaruto archipelago, a string of islands 40 km off the coast in the Indian Ocean dotted with luxury resorts.
But 300 local inhabitants were still stranded on the islands, where the cyclone reduced the resorts to rubble, and officials said boats were being dispatched to rescue them.