African Union assault on al-Shabaab strongold in Somalia: Somalia's al-Qaeda-linke Islamists , Amisom soldiers have taken control of Al shabaab stronghold and headquarters town of Kismayu.

Heavy Fighting is going on at the port of Kismayu as special forces and naval vessels destroy Al-Shabaab

Fierce fighting erupted outside Kismayo city and was continuing through the morning, residents and a Kenyan military spokesman said. The African Union offensive, which has been expected for weeks, involved land, sea and air forces, with helicopters strafing al-Shabaab emplacements and coalition reinforcements making their way to the city from the north.

Several hundred Kenyan soldiers staged an amphibious landing on Kismayo’s main beach at 2am on Friday, after launching off from Kenyan Navy ships patrolling close offshore. “Kismayo has fallen, with limited resistance,” Cyrus Oguna, Kenya’s military spokesman, said. “Kenyan maritime forces with Somali national army assistance landed with full surprise early this morning. There is some fighting still continuing, but we are in control.”

People living in the city, roughly midway between Mogadishu, Somalia’s capital, and the border with Kenya, said however that Islamist defence forces had fought back.

“The town is not yet captured,” said Jamac Ukun, contacted by telephone in Kismayo.

"Helicopters are flying over the town and they have launched several missiles on various bases. Many young men have taken their guns and are taking part in the fighting.

“There is no heavy fighting in the town, but the coalition forces came onto the beach with ships and battle wagons, and al-Shabaab are deploying their fighters. I can hear the fighting, there are heavy weapons.”

Al-Shabaab’s radio station was back on air and calling for the city’s residents to join the fight to repel the coalition troops, Mr Ukun added.

An Islamist spokesman said that they would “defeat the invaders, God willing” and would keep control of the city.

Kismayo, with a population estimated at 200,000 people, is al-Shabaab’s last major stronghold after a series of attacks by African Union peacekeepers forced them from other towns over the last six months.

The group, allied to al-Qaeda, earns most of its revenue from taxing imports and exports that pass through Kismayo’s port. Loosing control of the city will leave the Islamists bankrupt, one diplomat said.

But there are concerns that once it is pushed out, al-Shabaab will morph into more of a guerrilla army and will increasingly focus on suicide bombings and what security specialists call “asymmetric warfare”.

Already more than 12,000 people have fled Kismayo in the run-up to Friday’s offensive, the United Nations refugee agency, UNHCR, said.