At least 16 children have died in Solomon Islands over the past two weeks in an outbreak of diarrhoea around the country.
The country's health ministry said more than 1,000 people in six provinces have been affected and it has put out health alerts to contain the outbreak.
The country is still struggling to recover from the devastating floods in early April which left up to 60,000 people homeless.
The ministry said the highly contagious rotavirus was the cause of outbreaks in the capital Honiara, Guadalcanal and Gizo in Western Province.
An official with the Ministry of Health and Medical Services, Chris Becha, urged parents to take their children to a health clinic as soon as they showed signs of diarrhoea as it was a leading cause of death in under fives.
"Parents should request that their children be given oral rehydration salts and zinc to reduce the duration and severity of the illness, and ensure children take these medications as instructed," said Dr Becha.
Dr Becha said symptoms, including diarrhoea and vomiting, usually appeared between one and three days after being exposed to the virus.
The Red Cross in Solomon Islands was preparing to boost its efforts to tackle the outbreak.
A Red Cross sanitation engineer, Ana Zarkovic, said the aid agency has hygiene promotion teams ready to go.
She said she has heard of 19 deaths, mostly children under five.
"There's a definite need for hygiene promotion, for carrying out education to those communities that have been affected about ways to stop the spread of the disease," she said.
The health authorities said rotavirus is spread through person-to-person contact, contaminated objects, or contaminated food or drink and symptoms, include diarrhoea and vomiting.
The symptoms usually appeared between one and three days after being exposed to the virus.
In May, 24,000 children were vaccinated in a bid to prevent disease outbreaks due to the flooding.