Avalanches in Alaska have cut off the only roadway to and from the City of Valdez.

According to the Associated Press, the highway could remain closed for at least a week, if not "much longer," Transportation Department officials said Monday.

The first avalanches in the coastal city occurred last week and caused Richardson Highway to flood.

CNN reported that officials in the town of more than 4,000, urged residents to voluntarily evacuate when the avalanches started.

The only way for anyone to access the city while the highway traffic is halted will be by boat or aircraft.

State troopers in Alaska said Saturday that they were trying to stabilize the area, when two individuals disrupted the process by walking toward Valdez and refusing their orders to stop. The pair was ultimately flown to the city by helicopter and charged with disorderly conduct and obstruction of a highway, the AP notes.

Avalanches are rapid flows of snow that slide down a hill or sloping surface. They can accelerate quickly and grow in volume with more snow as they fall downward.