Lieutenant-Colonel Said Abeid Abderemane, former leader of the breakaway Comoran island of Anjouan, said he had returned to power on Saturday following the ousting of Major Mohamed Bacar.
"I will do my duty as a citizen," Abeid told AFP, confirming his return.
Allaoui Ahmed, head of a militia group closely linked to Abeid, told AFP by telephone the lieutenant-colonel had again become "president" of the separatist island.
Witnesses said they heard shooting in one part of the island at around 9:00 am (0600 GMT) and that local residents had barricaded themselves in.
It was unclear whether the shooting came from clashes between rival forces or was simply designed to intimidate people.
Ahmed said Bacar, who was ousted on Friday, was "nowhere to be found.”
The major, contacted by AFP on Friday evening, said he intended "to get the situation under control very quickly.” At midnight his phone was cut off.
Bacar, the head of the military police on Anjouan, took part in a coup that overthrew Abeid on August 9.
After first serving on a three-officer leadership committee, Bacar proclaimed himself "head of the Anjouan authority" after thwarting a coup attempt in September.
In a message read out on the radio on Friday evening, Ahmed said Bacar had been removed from power with immediate effect because he was "incapable of assuming his responsibilities" and said his successor would be announced on Saturday.
The militia chief criticized Bacar for "favoring plans to introduce a new constitution" that is to be put to a referendum on December 23.
The reform of the constitution is an effort to end the political crisis in the Comoros that was triggered when Anjouan unilaterally seceded from the central government on Grande Comore on August 3 1997.
The people of Anjouan are divided between those who support independence, those in favor of remaining in the Federation and those who back a compromise giving broad autonomy to the three islands: Anjouan, Moheli and the seat of the capital, Grande Comore -- MUTSAMUDU, Comoros (AFP)
