SANTO DOMINGO, Dominican Republic (AP) — Tropical Storm Franklin unleashed heavy floods and landslides in the Dominican Republic on Wednesday, after making landfall in the country’s southern region, killing at least one person and injuring two others.

The storm was expected to swirl for most of the day above the island of Hispaniola that the Dominican Republic shares with Haiti. Forecasters warned the storm could drop up to 12 inches (30 centimetres) of rain in the Dominican Republic, with a maximum of 16 inches (41 centimetres) for the country’s western and central regions. Meanwhile, up to four inches (10 centimetres) of rain are forecast for Haiti, with nearly eight inches (20 centimetres) for the country’s eastern regions.

“The population of the Dominican Republic must all be right now, without exception, in their homes, the homes of friends and family, or in shelters,” said Juan Manuel Méndez, emergency operations director.

The civil defence identified the man killed as Carlos Marino Martínez, saying he died in the city of San Cristobal after being swept away by flood waters. The agency initially said he was one of its volunteers, but later corrected the information saying it misidentified a uniform he was wearing. They did not provide further details. Two women in that city also were injured following a landslide and were hospitalised, officials said.

More than 300 people were huddled in shelters in the Dominican Republic, where emergency operations officials said they were looking for a 54-year-old man with mental health problems who went missing after he jumped into a creek late Tuesday. Another 280 people were evacuated from their homes to safer ground, with at least six communities cut off by heavy rains, officials said.

The storm also downed several trees and at least two light posts, with dozens of homes affected by floods that turned streets into rushing rivers. Authorities said the roof of one home in San Cristobal collapsed, as did walls of various buildings around the country.

“There’s a lot of damage,” Méndez said.

Meanwhile, authorities in neighbouring Puerto Rico, which was also hit by Franklin’s rain, were searching for two scuba divers missing south of the US territory in waters churned up by the storm.

The UN’s World Food Programme warned Wednesday that some 125,000 people in the Dominican Republic are living in areas that “are extremely vulnerable to landslides and flash floods because they live in poor, overcrowded settlements near rivers, creeks, and lagoons”.

Hércules Urbáez, a 41-year-old father of six who lives in the city of Barahona, where Franklin made landfall, said he and his family went to his mother’s house for safety.

“People have refused to leave,” he said.

On Wednesday afternoon the storm was centred about 40 miles (65 kilometres) south of Puerto Plata in the Dominican Republic, according to the National Hurricane Center in Miami. It had maximum winds of 40 mph (65 kph) with higher gusts and was moving northward at 13 mph (20 kph).

Rivers were swelling across the country, with one in the southern coastal city of Barahona lapping at shacks made of tin where one resident used plastic buckets to raise his mattress above his home’s dirt floor.

In the capital of Santo Domingo, José Abott, a 34-year-old graphic designer, monitored the water level of a river near his home via a WhatsApp group: “It always fills with water.”

Meanwhile, Tropical Storm Harold weakened into a tropical depression Tuesday night after making landfall in south Texas, bringing strong winds and rain, leaving thousands of homes without power.

Officials were most concerned about Franklin’s impact on Haiti, which is prone to catastrophic flooding given the country’s severe erosion.

“Haiti is among the most vulnerable countries in the world when it comes to the effects of extreme weather,” said Jean-Martin Bauer, the World Food Programme’s director for Haiti. In June a powerful thunderstorm that unleashed heavy rains left more than 40 people dead across the country.

Prime Minister Ariel Henry had urged Haitians on Tuesday to stock up on water, food and medication.

More than 200,000 people in Haiti have been displaced by gang violence over the past few years; authorities checked up on some of those living on the street or in makeshift shelters.

In the Dominican Republic officials shuttered schools, government agencie, and several airports, with at least 25 of the country’s 31 provinces under red alert. On Wednesday more than 400,000 customers were without power, and dozens of aqueducts were out of service because of heavy rains, affecting more than 1.3 million customers.

Flooding already had been reported on Tuesday in Santo Domingo and beyond, where residents prepared for heavy rainfall.

“We’re scared of the river,” said Doralisa Sánchez, a government employee who lives near the Ozama River that divides the city. She had to flee her home three times during previous storms.

She hoped Franklin wouldn’t force her to temporarily abandon her home because she said people steal belongings left behind.

The storm worried thousands of Dominicans who live in flood-prone areas.

“When two drops of water fall here, this suddenly becomes flooded,” said Juan Olivo Urbáez who owns a small business in a community near the Ozama River.

The National Hurricane Center issued a tropical storm warning for the Turks and Caicos Islands, where up to three inches (eight centimetres) of rain was forecast in some areas.

Franklin is the seventh named storm of the Atlantic hurricane season which runs from June 1 to November 30. An eighth named storm, Gert, dissipated on Tuesday.

On August 10 the National Ocean and Atmospheric Administration updated its forecast and warned that this year’s hurricane season would be above normal. Between 14 to 21 named storms are forecast. Of those, six to 11 could become hurricanes, with two to five of them possibly becoming major hurricanes.