Peugeot's Sebastien Loeb competes during stage four of the 2017 Dakar Rally between San Salvador de Jujuy in Argentina and Tupiza in Bolivia. Photo: Franck Fife, AFP

TUPIZA, Bolivia – Bad weather in Bolivia forced organisers to shorten the fifth stage of the Dakar Rally on Friday, leaving Englishman Sam Sunderland as the leader of the motorcycle event.

Sunderland benefited as the stage was curtailed to just 219km rather than the scheduled 692km linking Tupiza with the old mining city of Oruro, famous for its carnival.

KTM rider Sunderland was the fastest over the first part of the stage which could be raced as he landed his second stage success go top of the pile.

An hour into the car's stage, Frenchman Sebastien Loeb of Peugeot was leading stablemate Stephane Peterhansel.

Organisers said they had no choice but to curtail the day's action after racing on the tough terrain "became impractical owing to the poor weather conditions on the road to Oruro."

Earlier, Spanish Honda rider Joan Barreda had lost the lead in the motorcycle category after picking up an hour penalty for refuelling in an unauthorised area, allowing Chilean Pablo Quintanilla of Husqvarna to take the lead.

Barreda, who dominated the third stage from San Miguel de Tucuman to San Salvador de Jujuy in the north of Argentina, was demoted to seventh position overall, 41 minutes behind Quintanilla.

Three other Honda riders – France's Michael Metge, American Ricky Brabec and Portugal's Paulo Goncalves – were also slapped with the same penalty for illegal refuelling during Thursday's fourth stage.

The penalties are a blow for the Japanese team's bid to take the title from Austrian rivals KTM, unbeaten in the Dakar since 2002.

KTM had already lost defending champion Toby Price of Australia, who was forced to retire on Thursday after breaking his left leg in a fall.

Former champion Carlos Sainz of Spain was forced out overnight after his Peugeot was badly damaged in an accident.

Sainz, the 2010 winner, is the second top auto competitor to quit the race after former two-time winner Nasser Al Attiyah in a Toyota.

The Spaniard lost control of his vehicle, which rolled over just five kilometres from the finish of Thursday's gruelling fourth stage.

"I'm obviously very disappointed by this withdrawal," said Sainz, also a two-time world rally champion in 1990 and 1992. "I regret not being able to challenge."

Sainz had been provisionally third in the standings when misfortune hit more than seven minutes behind French race leader and Peugeot teammate Cyril Despres.