Fourteen soldiers were killed after their patrol was ambushed in northern Burkina Faso in one of the worst attacks on the army during a five-year-old jihadist insurgency, a security source said Thursday.

The new toll is double one furnished earlier for Wednesday's raid between Tinakoff and Beldiabe in northeastern Oudalan province, which borders Mali and Niger.

"Following yesterday's ambush against the detachment of troops at Tinakoff, the death toll is 13 soldiers and one gendarme," a security source told AFP.

The raid comes ahead of presidential and legislative elections on November 22.

Northern Burkina Faso has been badly hit by jihadists who began making incursions from neighbouring Mali in 2015.

More than 1,200 people have lost their lives and over a million have fled their homes.

The most recent attack was in September when four soldiers were killed.

President Roch Marc Christian Kabore, who is seeking a second term, launched his campaign last week by promising to bring back "peace" to the country.

But his critics say he has been unable to confront the growing jihadist threat during his first term.

Because of the unrest, residents of almost 1,500 villages out of some 8,000 in the country will not take part in the vote.

In September, parliament passed a law allowing the results to be validated even if polling did not take place everywhere.

Burkina Faso is one of the world's poorest countries, and its armed forces are under-equipped.

Last year, 4,000 died in Burkina Faso, Mali and Niger jihadist attacks or in ethnic violence fomented by the insurgency, according to the UN.