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.