BELIZE CITY, Belize (AFP) — Tropical Storm "Lisa" slowed on Thursday after making landfall in Belize, causing flooding and plunging parts of the country into darkness as it churned westwards.

The United States National Hurricane Center has downgraded "Lisa" from a hurricane to a tropical storm, noting that as of 0600 GMT, the eye hovered about 135 kilometers outside of Belize City and was moving towards Guatemala and southeastern Mexico at 19 kilometers per hour.

For the next day or so, the storm system is expected to pack a gusty punch and deliver heavy rain, swells and flash flooding to Central America's northern coast and the tip of the Yucatan Peninsula, further weakening as it moves inland.

"Lisa" slammed into the Sibun River just southwest of economic hub and former capital Belize City around 21:20 GMT on Wednesday, uprooting trees, downing power lines and inundating streets.

A state of emergency was declared in two areas, while a countrywide curfew was in effect until dawn on Thursday.

Some parts of the country were left without power as the storm lashed the tourist-popular coast with maximum sustained winds of around 80 kph.

"BEL is aware of power outages affecting several areas of the country," the utility wrote on Facebook on Wednesday night. "We assure the public that our teams are taking note of the reports of damages to the power system, including fallen power lines and poles."