The African Union (AU) has given Burkina Faso's military a two-week deadline to hand power to a civilian ruler or face sanctions.

The military takeover after President Blaise Compaore was ousted on Friday was unconstitutional, it said.

The military said a civilian-led transitional government would be established as quickly as possible.

Lt Col Zida took power after mass protests ended Mr Compaore's 27-year rule.

A popular revolt led to Mr Compaore's resignation, but the military takeover was against democracy, said AU official Simeon Oyono Esono, following a meeting of the body's Peace and Security Council in Ethiopia.

The AU would apply sanctions against Burkina Faso if the military failed to give up power within two weeks, he is quoted by Reuters news agency as saying.

The BBC's Emmanuel Igunza in the Ethiopian capital Addis Ababa says the sanctions could include suspension of Burkina Faso's AU membership and a travel ban on military officials.

The AU's Peace and Security Council is expected to meet again in two weeks' time to discuss the crisis, he says.