Al-Qaeda linked Shebab fighters Saturday abandoned their last bastion in Somalia, retreating from the port city of Kismayo almost a year after Kenya sent troops against the Islamists.
The withdrawal from the southern city that has been a key economic lifeline for the insurgents came a day after African Union troops launched a major assault to finally dislodge the rebels.
"The military command of Shebab mujahedeen ordered a tactical retreat at midnight" from Kismayo, Shebab spokesman Ali Mohamud Rage told AFP.
The fall of the port is the latest in a string of major losses of territory for the militia.
Residents confirmed that the Islamist fighters seemed to have moved outside city lines and that their radio station, Radio Andalus, had fallen silent.
"We don't know where they went to ... but early this morning the last military vehicle left the town," said Hassan Ali, a resident.
"Even their radio station is off air," he added.
Shebab fighters on the ground also confirmed what they said was a tactical retreat from the port, which has been a key source of revenue for the insurgents from exports of charcoal, as well as their main entry point for weapons.
"We got orders from our superiors to withdraw from the city. ... This is part of broader military tactics we have set for the enemy," Sheikh Mohamed Abu-Fatma, a Shebab commander, told AFP by telephone.
The exit leaves a power vacuum, at least temporarily. Gunmen killed four people including two clan leaders in the city on Saturday, a resident said.
"The streets of Kismayo are very insecure as more people came with weapons which were hidden during Shebab rule," Mohamed Ahmed Yare, a trader, told AFP.
The militia have responded to the loss of Kismayo by stepping up attacks in Mogadishu and within Kenyan territory.
Kenyan police said they arrested eight suspects in Yatta, near the border with Somalia, "during a random check", adding that they found two bombs in the suspects' luggage.
The Kenyan army said it would move into the city soon.
"Our air wing has been targeting suspected pockets of Shebab. Two key regional commanders of the group, Hassan Yakub and Abdikarim Adow, were killed by KDF air strikes," said Kenya Defence Forces spokesman Cyrus Oguna.
Rage said that the Shebab withdrawal was "done in an orderly manner after five years of proper Islamic Sharia law in Kismayo," and that his troops moved away "to prevent civilian deaths."
Residents said that the withdrawing Shebab busted open the gates of the main prison in Kismayo and the police station.
"Last night they released the prisoners from the jail and I saw three civilians shot dead by Shebab after being accused of spying.
"They left and not one of them is here today," resident Abdikarim Hussein said.
Eyewitnesses said some residents took to looting former Shebab administrative offices.
The Shebab seized Kismayo, estimated population between 160,000 and 190,000, from Somalia's weak central government in 2008.
It had been a vital lifeline for the Shebab since the African Union force in Somalia (AMISOM) reconquered most of Mogadishu last year and Ethiopian troops stripped them of other key cities in the west.
The looming assault on Kismayo caused an estimated 12,000 people to flee the city.
The Kenyan military has been aiming to take Kismayo ever since it rolled troops and tanks across the border to fight the Islamist extremists almost a year ago in retaliation for attacks inside Kenya.
The recapture of Kismayo is seen as a major boost to the newly established central administration in Mogadishu and paves the way for government troops backed by regional forces to reclaim much of southern Somalia.
Observers say the loss of Kismayo would leave the Shebab, who once controlled 80 percent of the country, unable to retain large swathes of territory.
The other key Shebab-held towns of Afgoye, Baidoa and the port of Marka have all fallen in recent months.
But in places where the Shebab have abandoned fixed positions, most notably in the capital Mogadishu, they have switched to guerrilla tactics and remain a threat.
Analysts have warned that the Shebab -- who implement an extreme form of sharia law in the areas they control, amputating hands of thieves and stoning "adulterous" women -- can sow just as much chaos with guerrilla tactics.
Shebab spokesman Rage warned that: "We are still in the outskirts of Kismayo and it will remain a battle zone. ... The enemy will not sleep peacefully."