According to the latest reports, tropical storm Olga left at least 11 people dead in the Dominican Republic and one dead in Haiti after drenching the Caribbean island of Hispaniola and moving west toward Cuba.

Dominican Republic authorities warned that the death toll could rise as there are many people missing after the storm hit Wednesday.

Flooding there forced tens of thousands of people to flee their homes. The heavy rain and the discharge of water from a dam caused the Yaque River to overflow its banks and flood the city of Santiago.

Many people were reported missing around Santiago, located about 250 kilometres north of the capital, Santo Domingo. Many of its residents were cut off from the rest of the country and climbed trees and their roofs to escape the floodwaters. President Leonel Fernandez promised to send help quickly to the victims.

The latest disaster, which Fernandez said had hit agriculture particularly hard, came on the heels of Hurricane Noel, which caused more than 100 deaths in the Caribbean in October.

Some 34,500 people were evacuated across the Dominican Republic because of the floods and an estimated 5,000 homes were affected, many of them completely destroyed, officials said, quoted by AFP.

Olga developed in the centre of the Caribbean, two weeks after the end of hurricane season. It has caused heavy rain on Hispaniola. Such weather often provokes dangerous flooding and landslides on the island the Dominican Republic shares with Haiti.

The Atlantic hurricane season ended Nov. 1. However, tropical storms in December and January aren't unprecedented.

Just a few days ago, hurricane experts Philip Klotzbach and William Gray, the two Colorado State University meteorologists, have announced that they forecast 13 named storms for 2008, including seven hurricanes, three of which will be classified as major.