Weather conditions proved too much for competitors in the Dakar Rally in Bolivia on Saturday.

The sixth stage of the 2017 event was cancelled after more than 12 hours of continuous heavy rain which began to fall on Friday.

By Saturday morning, when the Oruro to La Paz leg was scheduled to take place, much of the route was impassable, either due to floodwater, or up to 20cm of mud.

Up until now, the main hazards have been dust, the thin atmosphere, and sharp contrasts in temperature: from 40C on the plains to below freezing at altitudes of 5,000m.

Such altitudes affect both the vehicles, with vehicle power reduced by 20 percent; and the drivers, who are liable to altitude sickness.

At this time of the year, heavy showers are a regular hazard in the Andes. Warm, moist rising air encourages thunderstorms, which can be very slow-moving. The soils in the region are poorly aggregated, meaning they are very easily washed away as mudslides.

Fortunately Sunday is a scheduled rest day, giving organisers and competitors a chance to re-group and prepare for Monday.

Monday may also prove rather problematic as further heavy showers are expected.

An improvement in general weather conditions will occur on Tuesday, when a much lower risk of showers is expected.