The death toll from torrential rains in Central America over the past week has almost doubled since Saturday, with a further 25 lives lost in El Salvador, authorities said on Sunday.

A tropical depression that swept in from the Pacific on Wednesday caused mudslides and chaos on roads and forced thousands of people to abandon their homes in the chain of countries between Mexico and South America, killing 81 so far.

On Saturday, the death toll stood at 45 in the region, home to some of the poorest countries in the Americas. El Salvador, a nation of some 6 million, was the worst affected overnight, with accidents pushing up the number of victims there to 32.

"The situation has got even worse, it's still raining heavily in various parts of the country," El Salvador's president, Mauricio Funes, said in an address late on Sunday,

Many of those killed in the country died in mudslides, an official from local emergency services said.

The rainfall was so strong in the area around the municipality of Ciudad Arce, northwest of San Salvador, that rescue operations had to be suspended for a time.

Guatemala also reported more dead, bringing its death toll to 28, while the total rose to 13 in Honduras. At least eight people have also died in Nicaragua. No deaths were reported in Costa Rica, though dozens of families have been evacuated.

Rain was still falling in parts of the region. The weather has also hit southeastern Mexico, where swollen rivers have affected thousands of people, notably in Tabasco state.

At least four people died in Mexico earlier in the week when Category Two Hurricane Jova struck from the Pacific, forcing the country's busiest port to close.