Flooding and landslides from the first tropical storm of the season have killed at least 144 people and left thousands homeless in Central America.

Dozens of people are still missing and emergency crews are struggling to reach isolated communities cut off by washed-out roads and collapsed bridges caused by Tropical Storm Agatha.

Guatemala has been the hardest-hit so far, with officials reporting 120 dead and at least 53 missing.

In the department of Chimaltenango, a province west of Guatemala City, landslides buried dozens of rural Indian communities and killed at least 60 people.

In all some 110,000 people have been evacuated across the country.

Rescue efforts have been complicated by an eruption by the Papaya volcano on Thursday near the capital that blanketed parts of the area with ash.

But that has now tapered off allowing helicopters and small planes to deliver aid to communities still unreachable on washed out roads.

Thousands more have fled their homes in neighbouring Honduras, where the death toll rose to 15 as meteorologists predicted three more days of rain.

In El Salvador, at least 179 landslides have been reported and 11,000 people evacuated, with the death toll there reaching nine.

Agatha made landfall near the Guatemala-Mexico border on Saturday as a tropical storm with winds up to 45 mph. It dissipated the following day over the mountains of western Guatemala.