The Comoros, an unstable archipelago off the coast of East Africa, landed troops early Tuesday on the breakaway island of Anjouan to crush a year-old rebellion, one day after dropping leaflets warning the population. The government said its forces, backed by larger numbers of African Union (AU) troops, had taken control of the island's airport and main towns, and had urged rebel leader Mohamad Bacar to surrender.

A French-trained former police chief, Mr. Bacar faces federal charges of treason, usurpation of power, torture, and war crimes. Last year, he refused to step down after an election that authorities ruled illegal and has since continued to govern Anjouan as a separate state. Authorities have pledged to depose Bacar and install a transitional government to organize fresh elections for the island in May.

A victory for the AU in the tiny archipelago might offset its tattered reputation from largely ineffectual peacekeeping missions in Sudan and Somalia.

About 700,000 people live in the Coromos, an archipelago in the Indian Ocean near Madagascar. Some 300,000 reside in Anjouan, one of three main islands that make up the Coromos. The islands declared independence from France in 1975, and the country has since faced numerous problems arising from tensions between the islands and a central government.

Tuesday's amphibious assault on Anjouan began at dawn when mortar and machine-gun fire was heard on the island, the BBC reports. Around 450 Comoran troops supported by up to 1,500 AU military personnel were deployed. Defense chief of staff Mohamad Dosara said AU troops had entered the capital, Mutsamudu, where Mr. Bacar is believed to have the protection of several hundred armed police.

Bacar's whereabouts are unknown, phone lines to the island have been cut, and the BBC says authorities have been unable to confirm any casualties.

Agence France-Presse reports from Mutsamudu that Bacar's forces clashed with AU troops near his residence outside the capital, after apparently abandoning the presidential palace. In the city, however, Tanzanian soldiers entered without resistance to the cheers of local residents, according to witnesses.

Federal Comoran forces deployed with AU forces in the fight against Bacar, fired from a ship docked off the shore of Ouani, where heavy explosions and rifle fire could be heard, according to an AFP journalist.

Bacar's forces, tying red ribbons – the colour of the Anjouan flag – around the barrels of their assault rifles, were deployed on the road between Mutsamudu and Ouani and around the cliffs of the capital early Tuesday....

In an interview ... Thursday, Bacar had taken a defiant stand.

"I am still determined to defend Anjouan despite my concern that people are ready to come here and fire on the Anjouanese. But I am continuing with my preparations to defend Anjouan," he said.

The Associated Press says that a resident in Domoni, a coastal Anjouan town, had seen soldiers conducting searches of houses as troops hunt for Bacar and his allies. AU troops had already taken full control of the main seaport.

At least 80 AU troops from Tanzania were among the landing force, officials said, but only a handful of government soldiers were spotted by reporters. The troops apparently arrived aboard four ships that cruised earlier in the day along the coast toward the island's airport and seaport.

The morning's explosions and gunfire drew hundreds of people into the streets of Anjouan, some of them chanting "Bacar is a dog" and "We have won!"

A Comoran government official told Reuters that troops had met "a little resistance" in Mutsamudu. Federal authorities accuse Bacar of trying to secede from the republic, but he has claimed that his battle is for greater autonomy, not outright separation.

The Australian Broadcasting Corp. says that Comoran President Ahmed Mohamad Sambi announced the military operation Monday in a national televised address. France has also given its support to the seaborne assault on Anjouan.

Agence France-Presse reported Monday that leaflets dropped by Comoran military helicopters over Mutsamudu had warned residents of the imminent invasion.

The National Development Army "informs all the residents of Anjouan that it will be in Anjouan within days or in the coming hours," read the text, also seen by AFP.

"Residents are also advised not to go far from their homes," they added, urging pupils, fishermen, traders and farmers not do their daily activities 'until further notice.' "

Earlier this month, the BBC reported that France had helped transport AU troops to the Comoros in preparation for the assault. Tanzania, Sudan, Senegal, and Libya have offered troops for the operation.

In February, AU leaders agreed to support Comoros and commit troops to restore control over Anjouan after failed negotiations by Francesco Madeira, an AU special envoy. Mr. Madeira said time had run out for Bacar.

"I am afraid to say that if he tries to do that, it will be the end of him physically, if necessary," Mr Madeira said.

"He will be overwhelmed ... and what we are going to do in Anjouan is to take over the island, we will intervene to capture the island."

IRIN, a UN-run humanitarian news service, says that the republic has suffered 19 successful and attempted coups since 1975, including island secessions. After Anjouan and Moheli, another island, rebelled in 1997, African mediators brokered a new constitutional system that permits each Comoran island to elect its own president and to take turns as federal president.

A diplomat in Moroni, the capital on Grand Comore, the largest island, told IRIN in January that military action against Bacar appeared to have popular support, but said that the current political system may need overhauling, because it's troublesome and costly for a heavily indebted country.

"If the government regains control, they need to organise elections and then, when a legitimate [Anjouan] government is in place, authorities need to sit down together and have dialogue. They need to look at the current constitution and amend it. It is clear that it is not working - it leads to too much dispute - and having four governments [a union government and one for each individual island] is far too expensive."