African Union (AU) troops will arrive in Comoros in days to help the federal government wrestle back control of a renegade island, an AU official has said, Reuters said. Tensions have been rising across the coup-prone Indian Ocean archipelago since Mohamed Bacar, self-declared leader of Anjouan island, announced his victory in an illegal election last June. The federal government demanded he step down and is preparing to invade. The AU slapped sanctions on Bacar and his allies in October, then agreed last week to send troops too. "Within a few days you will begin to see our soldiers arriving here in Moroni," the AU's special envoy to Comoros, Francesco Madeira, told national radio late on Wednesday. Madeira said he had just returned from visiting Anjouan with officials from the Arab League, France and the United States. He said he had offered Bacar a chance to leave the island in peace, but that the rebel leader had rejected the proposal. "We want to avoid, to minimise as much as possible, the damage, collateral effects and the suffering of the population," the envoy said. The AU said on Monday that last ditch talks with Anjouan's leaders had failed and that military action was the only option.