The AU condemned any anti-constitutional change in line with decisions and declarations adopted at the summits in Algiers and Lome and under terms of the founding act of the African Union, said a statement.
The AU will also examine the situation in the Central African Republic and discuss measures to be taken for response.
Shooting broke out in Bangui on Saturday afternoon after unidentified armed men drove into northern part of the city where President Ange-Felix Patasse's residence is located.
The Central African Republic, boasting rich minerals including gold, diamond and uranium, has been plagued by coups and frequent changes of government since independence from France in 1960.
Saturday's coup attempt was the second in five months. Patasse survived a coup bid in October last year when he was supported by Libyan troops and fighters sent by a rebel leader in the neighboring Democratic Republic of the Congo.