An overnight landslide caused by flooding may have buried around 100 people trying to rescue victims of a previous landslide along the Inter-American Highway in the Guatemalan highlands.

Al Jazeera's Martin Asturias, reporting from the scene of the incident near the town of Santa Maria Ixtaguacan, said that 23 bodies have been pulled from the mud so far.

Those buried Sunday were working to rescue victims of a previous landslide, which swept over a bus on Saturday and killed at least 12 people.

The government estimates that 38 people have died in the past two days of flood-triggered landslides, but the 12 people killed Saturday combined with the 23 bodies recovered from the second landslide amounts to a death toll of 45 - a number that is likely to rise as more bodies are found.

Heavy rains on Sunday afternoon forced rescue work to be suspended until Monday, said David de Leon, a spokesman for the national disaster response effort.

'National tragedy'

Unrelenting rains and severe weather have lashed Guatemala for weeks, in what the country's president has called a "national tragedy".

Alvaro Colom, the Guatemalan president, declared a state of emergency. The president also told citizens to stay off the nation's highways to avoid more landslides.

At least 45 people have been killed in rain-triggered disasters across Guatemala [EPA]

The Inter-American Highway has been cut by more than 30 landslides in a 50-kilometre span. Guatemala's national radio station reported that other landslides created a traffic jams up to 75km long.

The highway is now "practically closed," Guatemala's government said Sunday. Week of heavy rain have caused flooding that have affected some 40,000 people in the country.

At least four other people died in a house in western Quetzaltenango on Saturday after it collapsed due to a landslide - adding to weather-related deaths from Friday.

Colom warned that 24,000 more people are at risk as the government runs out of funds to deal with the crisis.

"Top priority at present is dealing with this emergency. There are no funds left to deal with earlier disasters like the one caused by [tropical storm] Agatha," in late May, Colom said on Saturday after touring some of the affected areas.

High cost

He said weeks of heavy rains - including the latest torrent brought on by Hurricane Frank - had caused between $350-500 million in destruction across the country.

Meteorologists have forecast another 24-36 hours of heavy rain throughout much of Guatemala.

Meanwhile the weather forecast of more rain across Central America has prompted officials in Mexico to take precautions against landslides.

Heavy flooding in the Mexican Gulf state of Tabasco forced thousands of people from their homes, while authorities in neighbouring Chiapas and Oaxaca states, which border Guatemala, and the state of Veracruz also reported serious flooding.

"The bad weather in the southeast has caused the worst rainy season on record. We are marshaling aid for the affected area," Felipe Calderon, the Mexican president, wrote on his Twitter page.

Mexico's power company opened floodgates on some hydroelectric dams in the region, worsening the flooding in some low-lying areas, but no related deaths were reported.