A massive landslide buried up to 100 people in Guatemala trying to dig out a bus caught in deep mud as torrential rains battered the country.

The weekend death toll from slides and flooding caused by the rains has already reached 36 and the fire department said today that up to another 100 people may have been buried by a second slide on a major highway outside the capital.

‘A wall of earth fell on a bus and around 100 local people organized themselves to dig out the victims,’ said fire department spokesman Sergio Vasquez. ‘Then another landslide came along and buried them.’

Emergency workers have already recovered the bodies of 18 victims at the site but warn it could take up to two days to dig out all the corpses.

The incident follows another landslide on Saturday that buried a bus, killing 12 people.

Another six were killed on Saturday in separate incidents.

More than 30 separate landslides cut the Inter-American Highway, one of Guatemala's main roads, within a single 50kn (30 mile)stretch, local media reported.

Emergency services officials warned further rain was expected today and tomorrow.

Record amounts of rain have fallen in parts of Guatemala and southeastern Mexico this year.

Thousands of people in the Mexican Gulf of Mexico state of Tabasco have been forced from their homes by flooding.

Water levels behind some dams in the region have risen so high that floodgates have been opened.

President Alvaro Colom has declared a national emergency in the wake of the disaster.

Mr Colom said: '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 May.'

He said the rains could cost the country an estimated $500m (€387m).

Authorities in neighbouring Chiapas and Oaxaca states, which border Guatemala, and the Gulf state of Veracruz also reported serious flooding.

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