BOGOTA — Rescue workers raced on Sunday to find survivors of a flood and mudslide that destroyed a mountain town in Colombia as the death toll rose to more than 230, authorities said.

The surging water and debris appeared to have wiped out much of the provincial city of Mocoa, near the border with Ecuador. The torrent struck while most residents were sleeping, officials said.

The Colombian Red Cross reported that the number of those killed had risen to 234, though news outlets reported slightly higher figures.

Carlos Iván Márquez, head of Colombia’s natural disaster unit, told reporters that authorities believed more than 200 people had been injured in the mudslide, and that 600 had been evacuated to temporary shelters.

“We have a huge challenge to find the missing people,’’ he said.

More than 1,500 emergency workers have descended on the area to help find survivors.

The Colombian Red Cross said it had deployed 24 people, including psychologists and other specialists, to help find missing people.

“The entire capacity of the state is deployed to support the search and rescue,’’ President Juan Manuel Santos wrote on Twitter on Saturday.

The military was airlifting a few critically injured patients out of the area, the Associated Press reported.

The mudslide was triggered when a surge of water and debris plowed through Mocoa after a sudden downpour that lasted hours and caused nearby rivers to flood while most residents slept. The water, carrying mud and rubble, leveled many homes in its path and washed away large trucks.

“God bless, I don’t even want to remember this,’’ Marta Ceballos, 44, a street vendor, told RCN Radio. “Seeing how they, everyone screaming, crying, running, in cars, in motorcycles — and how the mud was enveloping everything, it was just too much.’’

Search-and-rescue teams combed through the debris Sunday and helped people who had been desperately clawing at huge mounds of mud by hand. Many had little left to search.

“People went to their houses and found nothing but the floor,’’ Gilma Diaz, a 42-year-old woman from another town, told the Associated Press. She came to Mocoa to search for a cousin.

Dozens stood in the door of a hospital, hoping for news of family members who were not on the list of those confirmed dead or injured. Others knocked on relatives’ doors, hoping to find someone with information about their loved ones.

A surgeon at a hospital in Mocoa, Dr. Herman Granados, said doctors were overwhelmed and that blood supplies were running low. Many people were still missing, he said.

According to the Red Cross, at least 25 homes were destroyed; 17 neighborhoods and 300 families were affected; and at least 202 people were injured. Of the 234 dead, 174 were identified, it said.

On Sunday, the city was effectively cut off from the rest of the country as some residents huddled in shelters, nearly all without water, electricity, or gasoline.

Survivors charged cellphones using car batteries so that they could reach loved ones in other towns.

“There’s not a single drop of drinkable water; we need water, that’s what’s urgent, and there’s nothing to eat,’’ Marisol González, the head of a nearby technological institute, told El Tiempo newspaper.

Colombia’s weather service was predicting light rains on Sunday, precipitation far less extreme than what hit the region before the mudslide.

The disaster seemed to hit young people particularly hard. Santos said more than 40 of the dead identified so far were under 18, perhaps because youngsters were already in bed when the floodwaters struck.

Maria Cordoba, a 52-year-old resident who was trying to wash her belongings in a river, said two of her nephews, ages 6 and 11, were killed when their house was destroyed.

A rescue worker in an orange jumpsuit emerged from one search area with the body of an infant wrapped in a towel. Not far away, Abelardo Solarte, a 48-year-old resident of Mocoa, held a child’s shoe as he helped clear debris.

Jair Echarri, who came from a nearby town to help, also struggled to comprehend the loss of so many children.

“I feel an enormous sadness because it’s filled with kids’ things, toys, clothes, school books,’’ he said. “I am a father and this breaks my heart.’’

Mocoa is vulnerable to flooding. It is surrounded by the three rivers in a natural basin created by the surrounding mountains.

The danger has grown worse in recent years because of deforestation, which eliminates some protection from runoff, and because many people built their homes close to the water. But the triggering event was rainfall of more than 5 inches that began late Friday.

A 1989 hydrology report for the Agricultural Ministry warned that just such a disaster could happen unless steps were taken to reinforce the riverbanks, channel water away from the town and restore some of the forest. It was not immediately clear why those steps had not been taken.

Colombian officials pledged aid to rebuild homes, and the attorney general launched an investigation into whether local and national authorities responded adequately to the disaster.

Material from the Associated Press was used in this report.