(CNN) -- Officials in Costa Rica worked Friday to mop up the damage after heavy rain and mud slides buried homes and killed at least 23 people in the Central American country, authorities said.
Crews have found at least 20 people who were buried alive Thursday after pounding rains sent mud rushing over at least five homes in San Antonio de Escazu, a suburb of the nation's capital, the Costa Rica National Commission for Emergencies said.
Several people were still reported missing there Friday, while three people were found dead in San Marcos de Tarrazu, a city in the central part of the country, said CNE.
Another 2,639 people have sought refuge in 46 shelters, the commission said.
President Laura Chinchilla has declared a state of emergency and said that Friday and Saturday would be national days of mourning. She visited an affected area in San Antonio de Escazu Friday to offer her support to the families missing loved ones.
Images airing on CNN affiliate Teletica showed rescue crews digging through demolished homes. In another scene, workers at a mud-covered overturned vehicle spread a white sheet over a victim's body.
Other images showed buckled roads damaged by the ferocity of the rushing water. In another area, some residents strung up a rope between two banks so people could hold on to it and walk across rushing water.
Mud slides and flooding were reported in many places in the Central Valley area, which is surrounded by a handful of mountains and volcanoes. It is the most populous part of the nation.
Classes were indefinitely canceled at many of Costa Rica's public schools, the education minister said on Teletica.
About 800,000 people were left without safe water supplies, and residents were told to boil any water to be used for drinking or cooking.