Burkinabe troops fanned out across the capital, Ouagadougou, with security stepped up at key sites as visiting Benin President Thomas Boni Yayi pledged that west African nations would fight back against a mounting terrorist threat.
"We're not going to just sit on our hands. We will react and respond," he said, speaking on behalf of the 15 regional nations.
"The question is whose turn is it next," Boni Yayi added.
Friday's attack by Islamist gunmen on a four-star Ouagadougou hotel and nearby cafe left at least 29 people dead, around half of them foreigners.
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The first such incident in the country, it came weeks after Islamists claimed an assault on a top hotel in Bamako, capital of neighbouring Mali, where 20 people died.
At the crime scene, an 18-strong team of French investigators, including forensic experts, joined local police in white coats combing for clues at the Splendid hotel and Capuccino cafe stormed by the gunmen.
The French foreign ministry said 30 people had been killed and 20 identified.
In a statement carried by US-based monitoring group SITE, AQIM said the Splendid Hotel was "one of the most dangerous dens of global espionage in the west of the African continent."
It published photos of the three young gunmen dressed in military fatigues and wielding weapons, identifying them as Battar al-Ansari, Abu Muhammad al-Buqali al-Ansari and Ahmed al-Fulani al-Ansari.