Abu Mansoor said al-Shabaab will fight "oppression" elsewhere once Ethiopian forces are defeated [AFP]

"Once we are successful with that we will fight on and finish oppression elsewhere on earth," he said.

Al-Shabab, meaning youth, split last year from the Islamic Courts Union which controlled much of Somalia, including the capital Mogadishu, until it was pushed out by government and Ethiopian troops in 2006.

In depth

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"We shall welcome any Muslim from any part of the world who wants to join us. We will allow him to wed our daughters and share our farms."

The group was created in 2001 by four Somali men who had trained in Afghanistan and is listed as a "terrorist organisation" by the US.

Relative peace

The Islamic Courts Union brought relative peace to the Horn of Africa nation during its six months in control, enforcing strict laws and renewing hopes that the Somalia would become stable enough to allow aid agencies the freedom to operate.

However, their defeat by the Ethiopian and government forces has brought renewed violence as various anti-government forces have mounted near-daily attacks.

In Marka, Al Jazeera found people welcoming al-Shabab and dressing their children like the fighters who have been the only people to bring some semblance of peace to Somalia in recent years.

More than one million people have been displaced by the fighting in Somalia, one third of the population rely on emergency food aid and the chaos has helped fuel kidnappings and piracy off the coast.