Two detainees have died after a van was swept away by rising floodwater in South Carolina, authorities said.

A sheriff’s office van was carrying two detainees and two officers from Conway to Darlington when it was engulfed by water, according to Horry County Sheriff’s Department spokeswoman Brooke Holden.

The van was travelling near the Little Pee Dee River, one of the bodies of water officials in South Carolina are watching closely as water pours into the state from upriver in North Carolina following the heavy rains of Storm Florence.

Marion County Coroner Jerry Richardson confirmed that two women died in the incident. Their names have not been released.

Ms Holden said the two deputies tried to free the detainees out but could not open the doors. High-water rescue teams plucked the officers from the top of the van.

The incident is being investigated by the State Law Enforcement Division.

Forecasters predict some rivers in the north-east of the state might not reach their highest levels until later this week or next week.

In North Carolina, governor Roy Cooper pleaded with thousands of Florence evacuees to be patient and not return home yet.

The city of Wilmington is still mostly an island surrounded by floodwater, and people are waiting for hours for handouts of necessities like food.

Mr Cooper told a news conference it was hard for residents to leave home, and it is even harder for them to wait to go back, but many roads are dangerous and new hazards are possible as water recedes.

Officials said about 10,000 people are in shelters.

Aides said President Donald Trump will visit North Carolina on Wednesday to see the damage. He has already tweeted that any criticism of the government response is a “total lie”.