Since Sunday, three people have died due to the storm in El Salvador and one in neighbouring Honduras, according to civil protection authorities.

In both countries and in Guatemala, hundreds of people have been evacuated from high-risk areas and taken to temporary shelters.

Pilar was about 260km off the coast of El Salvador on Wednesday, generating winds of about 97kph the US National Hurricane Center (NHC) said in a bulletin.

“The centre of Pilar will continue to move away from the coast of Central America this afternoon and tonight,” it said, adding that “gradual weakening” was forecast for the coming days.

However, the NHC warned that “heavy rainfall and flash flooding (are) still a threat over portions of Central America.”

El Salvador’s environment minister Fernando Lopez said the country was maintaining a high alert level.

“We cannot let our guard down… there is a lot of accumulated water, there could be river flooding and landslides.”

The country’s small farmers’ association said many crops were flooded but the full extent of the damage had not been quantified.

Honduras also has an alert in place for coastal areas, while in Guatemala, emergency services are steeling themselves for possible flash floods.

Pilar arrived on the 25th anniversary of the Atlantic Hurricane Mitch, which left some 9,000 dead in the region.

Covering 523,000 sq km and with 50 million inhabitants, Central America is highly vulnerable to intense meteorological phenomena.

Farther north along the Pacific coast, Mexico was still recovering Wednesday from the devastating Hurricane Otis, which slammed into the city of Acapulco last week as scale-topping Category 5, killing at least 46 people.