The Solomon Islands government says there are still up to 10,000 people in 24 evacuation camps after flooding that claimed 21 lives.
The Red Cross says there are at least two people still missing.
The Permanent Secretary for the ministry of women, youth, children and family affairs, Ethel Sigimanu, says she is concerned about pregnant women in the centres.
She says the government's main concern now is to improve sanitation in the camps to prevent disease.
"The diet is not mixed with vegetables or things like that. It's normally rice and noodles and fish. So there are nutritional issues as well. One major issue is to do with sanitation. Where you have a camp that houses about more than a thousand people, there are not enough toilets, the water is not sufficient."
Ethel Sigimanu says the strong earthquake off the coast of Bougainville yesterday was felt in Guadalcanal but she has not heard of any casualties from it.
The flooding has affected around 52,000 people, which is 10 per cent of the population.