UPDATE 6-Burkina Faso opposition parties, African Union reject army takeover
* Presidential guard officer had challenged top army general
* 'This is a popular uprising, not a coup,' officer says
* Former president Compaore in Ivory Coast after resigning
* Army general had initially claimed presidency
* Washington condemns military's attempt to impose its will (Adds U.S. government statement)
By Mathieu Bonkougou and Nadoun Coulibaly
OUAGADOUGOU, Nov 1 (Reuters) - Burkina Faso's opposition parties, the United States and the African Union rejected the army's seizure of power in the West African country on Saturday after the resignation of President Blaise Compaore, setting the stage for fresh street protests.
The military top brass named Lieutenant Colonel Isaac Zida, deputy commander of the elite presidential guard, as head of state on Saturday. A power struggle within the armed forces was resolved by sidelining the chief of staff.
Zida, who has operational control over the army's best trained and equipped unit, had declared himself interim president in an early morning radio address, overruling military chief General Honore Traore's claim to lead a transitional government following Compaore's departure. Continued...