African Union and Somali troops combed the Somali port of Kismayu on Wednesday for bombs hidden by al Qaeda-linked militants who fled their last urban bastion but warned of retaliatory strikes, the two militaries said.
The retreat signalled the demise of al Shabaab as a quasi-conventional military force, say analysts who expect the militants to resort increasingly to suicide bombings and hit-and-run attacks similar to those that rocked the capital Mogadishu over the last year.
Despite losing ground to AU and Somali military forces, al Shabaab, which counts foreign al Qaeda-trained fighters among its ranks, is still regarded as one of the biggest threats to stability in the Horn of Africa and a restoration of effective government in Somalia after two decades of violent disorder.
Al Shabaab gave notice of its intent to fight back in Kismayu by setting off a bomb in its centre on Tuesday, when Kenyan soldiers fighting under the AU flag also carried out at least two controlled detonations at the seaport.
"I have reports other IEDs (improvised explosive devices) have been found today on the way out to the seaport," Kenyan army spokesman Colonel Cyrus Oguna said by phone from Kismayu airport, now held by Somali government troops and allied forces.
Mohamud Farah, spokesman for government forces in Somalia's southern region of Juba, added: "We are looking all over the town, in particular the airport, seaport and all former rebel bases including the presidential palace."
The Islamist militants abandoned Kismayu, their primary redoubt in south Somalia, on Friday night following an assault on the city by air, sea, and land forces.
An al Shabaab spokesman said, however, that the withdrawal was tactical and that the group was far from defeated.
"We have not been destroyed. Don't think we are powerless. Only the most foolish person believes that al Shabaab will become extinct," rebel spokesman Sheikh Ali Mohamud Rage said.
Somali troops were to conduct house-to-house searches to flush out rebel remnants suspected to be still lying low in Kismayu, Oguna said. Six orphans were wounded late on Tuesday when a grenade was thrown at a boarding school.
KHAT FOR SALE
The most telling sign of the militants' exit may be the rapid return to Kismayu's streets of a natural narcotic known as "khat", the trade of which provides livelihoods for vendors and importers but was outlawed by the hardline Islamist al Shabaab.
Residents said khat - a leafy twig hugely popular among Somali men - was back on open sale in the market.
"Al Shabaab taxed khat for over three years. (They) then completely banned khat five months ago," resident Ismail Sugow told Reuters. "Some people tried to sell it on the black market but the militants burnt cars transporting it and arrested and fined anyone found selling, buying or chewing."
Al Shabaab's austere application of Islamic law alienated many Somalis, who objected to the executions and amputations meted out by insurgents who also banned football, music and forbade women from wearing bras.
Even so, the Kenyan troops and their Somali counterparts are having to earn the trust of a local population in a city that has frequently changed hands during more than two decades of violent disorder in Somalia. "They are friendly, they have not looted," local elder Osman Khalif said.
In neighbouring Kenya, the region's biggest economy, residents of Garissa, a mainly Muslim town near the eastern border with Somalia, fear al Shabaab or sympathisers were behind a spate of attacks meant to avenge the fall of Kismayu.
Kenyan police said this week that security forces were on high alert amid intelligence reports suggesting the militants will look to carry out more, high profile attacks beyond Somalia.
"The insecurity in this town is getting out of hand and the government is doing little to deter terror attacks," said local trader Stephen Mwika, referring to the fatal shooting of two police officers in Garissa on Sunday.
(Additional reporting by Abdisalan Ahmed in Garissa and Richard Lough in Nairobi; Writing by Richard Lough; Editing by James Macharia and Mark Heinrich)