At least 20 people have been killed in a militant attack in Burkina Faso's northern border region, the authorities have said.

Nineteen of the victims are said to have been officers in the military police and one was a civilian.

The militants targeted an outpost near a goldmine in Inata.

Two days earlier seven police officers were killed in another attack in the region, which borders Mali and Niger.

Islamist militants with links to al-Qaeda and the so-called Islamic State state group operate in the frontier area.

The three countries, backed by Chad and France, have deployed hundreds of troops there.