impassable

The authorities there have ordered a mandatory evacuation of Hatteras Island, warning that the main highway linking Hatteras to other islands could become impassable.

“Normally you would only portage a very small section of the river around an impassable rapid, maybe a waterfall or something,” he said.

The city's busiest road, which connects the centre with the international airport, is impassable, as is some of the motorway that connects the capital to the country's main port, Matadi.

A concrete UN sign that used to stand over the camp's now impassable main entrance has been knocked down.

"Whiteout conditions will make travel extremely hazardous, with impassable roads and a high risk of motorists becoming stranded," the NWS warned.