(Adds details of storm and extent of damage)
By Sarah Peter
CASTRIES, St. Lucia, Sept 29 (Reuters) - Tropical Storm Matthew strengthened to a hurricane on Thursday after triggering flooding and landslides on eastern Caribbean islands that killed one person, and was forecast to grow more powerful as it heads toward Jamaica, Haiti and Cuba.
Packing winds of up to 75 mph (120 kmh), Matthew was about 150 miles (240 km) northeast of Curacao and traveling westward, the U.S. National Hurricane Center (NHC) said.
Matthew whipped through the Caribbean islands of Barbados, St. Lucia and St. Vincent and the Grenadines on Wednesday, shutting international airports, ripping down power lines and trees, and forcing residents into shelters.
St. Vincent and the Grenadines Prime Minister Ralph Gonsalves told reporters one death had been reported in connection with the storm. He said there were 350 people in shelters in his country. In St. Lucia, floods and landslides threatened villages, sending some residents into shelters.
The storm is expected to veer off its westerly path and head north to Jamaica and Haiti on Sunday, bringing winds as strong as 100 mph (160 kph), the Miami-based hurricane center said.
Some projections show Matthew reaching the U.S. Eastern seaboard next week, but forecasters warned it was difficult to predict the course so far ahead of time. (Additional reporting Robert Edison Sandiford in Bridgetown and Frank Jack Daniel in Mexico City; Editing by Matthew Lewis)