ROUGH CUT (NO REPORTER NARRATION)

STORY: Somalia's al Shabaab rebels retreated from the southern port of Kismayu overnight on Friday, the group and residents said, abandoning the last major bastion of their five-year revolt after an offensive by African Union and Somali government troops.

The loss of Kismayu a day after it was attacked by Kenyan and Somali soldiers backed by air strikes will deal a major blow to the al Qaeda-linked rebels, weakening morale and depriving them of revenue from taxing local businesses and shipping.

But the withdrawal is unlikely to mark the end of its five-year rebellion.

The insurgents, who once controlled large swathes of the lawless Horn of Africa country, have been turning to guerrilla-style tactics, attacking the country's government with suicide bombings and assassinations.