Hurricane Beryl strengthened on Monday into a "potentially catastrophic" category 5 storm as it moved across the eastern Caribbean, putting Jamaica near its path after downing power lines and flooding streets elsewhere, Reuters reported.

Beryl brings an unusually fierce and early start to this year's Atlantic hurricane season, with scientists saying climate change probably contributed to the rapid pace of its formation as global warming has boosted North Atlantic temperatures.

By 11:00 AST (0300 GMT) on Monday, Beryl, packing winds of up to 160 mph (257 kph), was about 840 miles (1,352 km) east-southeast of Kingston, the Jamaican capital, the US National Hurricane Centre (NHC) said.

The storm struck the Caribbean region earlier in the day as the earliest Category 4 storm on record, rated on the five-point Saffir-Simpson scale.

Jamaica issued a hurricane warning on Monday, while tropical storm warnings were in effect for parts of the southern coasts of the Dominican Republic and Haiti.