France has warned against travelling to eastern Burkina Faso and its famed "W" nature reserve, home to large West African mammals including its last wild elephants, due to mounting fears of jihadist attacks.

A travel warning on the French embassy's website said that "due to a specific and certain threat, all of the park is classified as a red zone," with the neighbouring north-west region classified an orange zone.

"You must not travel to the park or the orange zone nearby," it said.

The "W" nature reserve is a major West African national park formed around a meander in the Niger river that is shaped like a W, and that spans three countries, Niger, Benin and Burkina Faso.

Run by the three countries and popular with tourists, it is on UNESCO's World Heritage List.

Burkina has seen several jihadist attacks on its borders this year, the worst of them taking place last month on the border with Mali, killing four people.