African Union-backed Somali government troops attacked hardline Shebab insurgent positions at dawn on Friday in the war-torn capital of Mogadishu, officials said.

An artillery barrage first poured down on a northeast district -- which AU forces claim was already largely abandoned by civilians -- before tanks and ground troops moved into the area.

EU foreign ministers on Monday extended the bloc's Somali anti-piracy mission Atalanta until December 2014, but did not act on plans to attack pirate gangs on land as well as at sea.

Ministers "agreed to extend the mandate of EU-NAVFOR Atalanta until December 2014", a statement said as talks focused on Syria and Serbia began in Brussels.

A missile strike killed four al-Qaida allied Shebab rebels in war-torn southern Somalia, officials and witnesses said Friday.

"An Al-Qaida commander was targeted in Lower Shabelle early on Friday morning, a missile struck and destroyed his vehicle, killing him and several colleagues," said a Somali government official.

International powers called Thursday for urgent action on Somalia, warning that the world will "pay the price" for failing to help the country tackle political unrest, Islamist militants and pirates.

But as officials from 50 countries and organizations gathered in London to discuss how to end two decades of unrest, Somalia's al-Qaida-allied Shebab insurgents vowed to "wage war" against any international peace initiative.

International powers called Thursday for urgent action on Somalia, warning at a meeting in London that the world will "pay the price" for failing to tackle political unrest, Islamist militants and pirates.

British Prime Minister David Cameron, U.S. Secretary of State Hillary Clinton and U.N. chief Ban Ki-moon were among officials from about 50 countries and organizations gathered to discuss a roadmap for Somalia's fragile government.

Two heavy blasts rocked the strategic Somali city of Baidoa hours after Ethiopian and pro-government forces wrested it from al-Qaida-allied Shebab insurgents, officials and witnesses said Thursday.

"Heavy losses were inflicted on the enemy after two explosions struck them when they entered positions our fighters had emptied," Shebab spokesman Sheikh Abdulaziz Abu Musab said, claiming responsibility for the blasts.

The U.N. Security Council unanimously agreed Wednesday to increase the African Union force in Somalia from 12,000 to 17,731 troops.

A resolution passed by the 15-nation council gave the African force a tougher mandate to attack Shebab Islamist militants and substantially increased international funding for the military operation.

Truckloads of Ethiopian and Somali troops on Wednesday captured the strategic Somali city of Baidoa from Al-Qaida-allied Shebab insurgents, who vowed to avenge the loss.

"We have taken control of Baidoa without a single shot, it is a great day for the people who are now welcoming us warmly," said Muhidin Ali, a Somali government military commander in Baidoa.

The U.S. special envoy for Somalia on Tuesday urged support for Somali regions seized from the al-Qaida-linked Shebab rebels controlling swathes of territory, but now under pressure from regional armies.

James Swan said local authorities should be bolstered in the Mogadishu outskirts recently captured by African Union forces, and in southern and western Somali regions where Kenyan and Ethiopian forces are battling the insurgents.

Gunmen believed to be Somali Shehab insurgents killed a Kenyan policeman in the northeastern border region with war-torn Somalia, the latest in a string of attacks, police said Sunday.

"We lost one officer in the raid late on Friday night, and another person shot in the attack is still in hospital," a senior police officer in the region, speaking on condition of anonymity, told Agence France Presse.