At least 16 people have been killed after floodwater tore through a campsite in Arkansas, US, on Friday.

The flood also washed away records of who was there, making the daunting search for dozens missing in heavily wooded forest even more difficult as anguished families waited for word of their loved ones.

Rescue crews planned to resume their search yesterday morning in the Ouachita National Forest, where heavy rain caused the normally quiet Caddo and Little Missouri rivers to burst their banks early on Friday. The search was expected to take several more days – and perhaps even weeks.

"It's like a nightmare that someone's wanting to wake up from, but you can't," said Major Harvey Johnson of the Salvation Army.

The floodwater, which rose as quickly as two metres an hour, poured through the remote valley with such force that it peeled asphalt off roads and bark off trees. Cabins dotting the river banks were severely damaged. Mobile homes lay on their sides.

A call centre set up for people to report loved ones who may be missing atAlbert Pike Recreation Area, a 54-unit campsite, received enquiries about 73 people on Friday.

At least two dozen people were taken to hospital. Officials had rescued dozens more before suspending their search at nightfall on Friday.

Brigette Williams, spokeswoman for the American Red Cross in Little Rock, estimated that up to 300 people were in the area when the flood swept through.

Forecasters had warned of the approaching danger during the night, but campers could easily have missed those alerts because the area is isolated.