A hurricane gathering force as it swept in from the Caribbean was threatening flooding and mud slides in Belize on Thursday after making landfall in the middle of the night, officials warned.

Hurricane Earl was packing sustained winds of 130 kilometers (80 miles) per hour, the US National Hurricane Center (NHC) said.

Its core was expected to strike near Belize City, the capital of the small Central American nation, around midnight Wednesday (0600 GMT Thursday).

The heavy rains it was carrying "could cause flash floods and mud slides especially over higher terrain," Belize's National Emergency Management Organization said in a bulletin.

"For coastal areas, there is also a risk for flooding, especially in low-lying areas."

Nearby Guatemala, Honduras and southern Mexico also issued alerts. Airports in northern Honduras were closed.

The outlying rim of the storm was already dumping rain on Belize after dousing northern Guatemala and Honduras's Bay Islands in the Caribbean.

Earl was expected to weaken as it continued west from Belize City, farther inland.

The fifth named tropical storm of the 2016 season, Earl strengthened to a Category 1 hurricane on Wednesday, according to the NHC. Winds initially measured at 120 kilometers per hour picked up just before landfall.

Category 1, the lowest of five grades on the hurricane scale, is described as having dangerous winds of between 119 and 153 kilometers per hour that can rip off roofs, bring down trees and cause extensive damage to power lines.

- Shifting path -

Belizean officials said the trajectory of Earl had changed late Wednesday.

Initially, the eye of the hurricane was projected to pass south of Belize City, but now it was seen to be on a path north of the city, population 60,000.

Belizean public and private workers were permitted to go to their homes Wednesday to secure property.

Officials warned that people living on the ground floor "will experience flooding" and some older wooden buildings would likely be destroyed.

The authorities opened 29 shelters.

The hurricane was forecast to continue westward into largely rural northern Guatemala and then, as a weaker storm, into Mexico's southern states of Campeche, Quintana Roo, Tabasco and Yucatan.

Guatemala in particular is prone to rainy season flooding and mudslides that often prove fatal.

Guatemala's population, at 16 million, is much bigger than the 330,000 in Belize, Central America's only English speaking country.