New York, Sep 6 (DPA) The United Nations has said it was rushing relief assistance to some of the worst-hit Caribbean islands, with Haiti and Cuba heading the list, while damage and threats to residents were being assessed.

John Holmes, chief coordinator of the UN humanitarian emergency programme, said Friday that the Bahamas, Jamaica and the Dominican Republic have been affected by heavy flooding.

The Caribbean has been hit by three Atlantic storms and hurricanes in three weeks, with the latest - Tropical Storm Hanna - now heading towards southeastern US.

'The damage is bad enough, but it will take some time to determine the extent of it,' Holmes told a press conference at UN headquarters Friday.

Holmes said it was too early to give a clear report on the extent of the damage and the condition of affected people in the region. Some islands, such as the Dominican Republic, have not yet requested assistance or reported on the destruction.

Worst-hit Haiti suffered 'very severe' damage, with 100 to 200 deaths, Holmes said. On Friday, Haitian officials reported at least 136 deaths. Holmes said an estimated 600,000 Haitians need help, including 250,000 in Gonaives district alone.

Holmes said the UN planned to launch an appeal for donations in coming days to assist Haiti and other Caribbean islands. UN agencies have deployed workers while the UN peacekeeping force in Haiti was helping with evacuations in flooded areas.

Hurricane Gustav ravaged Cuba last week, destroying up to 100,000 homes and 500 schools.