Communities across earthquake-ravaged Haiti are in desperate need of help after the island nation was lashed by Tropical Storm Isaac, according to British aid agencies.

Charity workers are battling to get emergency supplies to the worst-hit islanders after they endured torrential downpours and near hurricane strength winds.

According to reports, a woman and a child died in the town of Souvenance, and a 10-year-old girl died in Thomazeau when a wall fell on her. More than 5,000 people have had to be evacuated from their homes.

Makeshift camps, built after the island was rocked by a massive earthquake in 2010 that claimed the lives of more than 220,000 people, have been destroyed. The storm has also laid waste to crops, knocked down telephone lines and wiped out power supplies in the worst-hit areas, say aid workers. Fears are also mounting over the impact of flooding and disease for the thousands of people living in refugee camps.

According to Oxfam, camps in the capital Port-au-Prince, such as Jean Marie Vincent, have been flooded, as well as towns in the south of the island, including Les Cayes, Jacmel and Nippes. Heavy rainfall is forecast in the wake of the storm, with up to 20 inches of rain predicted in Hispaniola.

The charity said that nearly 400,000 Haitians still living in refugee camps after the earthquake remained "highly vulnerable" to the threat of flooding, landslides and water borne diseases, especially cholera.

It said it had sent emergency teams to the affected areas of the island to carry out in-depth assessments and to provide aid to those who need it in the form of clean water, hygiene kits and public information about sanitation.

Jane Cocking, Oxfam's humanitarian director, said: "The storm may have passed but living conditions in Haiti remain so challenging for so much of the population that it's far too early to say the threat is over. People in Haiti have so little that they are incredibly vulnerable to the risks posed by flooding and disease. They remain in desperate need of our help."

The aid agency is in the process of contacting its supporters to ask for donations to help support its emergency work in Haiti, which is often cited as the poorest country in the western hemisphere with four in five of the population living on less than two US dollars a day.

Isaac was heading towards eastern Cuba and forecasters said it poses a threat to Florida on Monday and Tuesday. In Cuba a state of alert has been declared in six of its eastern provinces and five central provinces were put on preliminary watch. In Florida governor Rick Scott has declared a state of emergency as the storm approaches the southern American state. The storm, which was centred about 95 miles east-southeast of Guantanamo Bay, Cuba, earlier on Saturday, is expected to pass up the Gulf of Mexico to the west of Florida as a hurricane on Monday.

The Press Association, photo by Marcello Casal Jr