The armed Islamic extremist group al-Shabaab, which has caused so much misery in Somalia in recent years, has lost the last city under its control. Kenyan military officials report that African Union troops stormed the southern port of Kismayo early this morning. Reports are still incomplete, but if al-Shabaab has in fact been forced out of Kismayo, it's a serious blow to the much-feared group, which has been slowly losing its grip on Somali life.

Somalia has struggled for nearly 20 years without a central government as warlords and militias have battled for control. Al-Shabaab, an al-Qaida-affiliated militia which promotes an extreme interpretation of Islamic law, began an insurgency in 2006. Eventually, it controlled large swathes of the country, including parts of the capital city, Mogadishu.

The group's steps towards establishing a medieval Islamic state included banning music and art, and punishing violators with stoning and amputations. Interference with foreign food aid during a 2011 drought helped trigger a famine in which tens of thousands starved.

Al-Shabaab's harsh rule turned many Somalis against them, and they were pushed from Mogadishu last year by an African Union force, leaving the capital for the first time completely in government hands. Now a new Mogadishu-based government, elected by clan chiefs, is working to write a new constitution which it's hoped will lead to nationwide elections next year. Al-Shabaab will be severely damaged by the loss of Kismayo – a lucrative source of "taxes" extorted from businesses and the port, as well as a strategic base of operations near the Kenyan border.

But the militia still controls much of the countryside in central and south Somalia, and the peace in Mogadishu is fragile. The jihadists continue to launch effective terrorist attacks against the fledgling government, even in the capital. Al-Shabaab has shown its ability and willingness to strike anywhere in the country.

It's not over yet, but it's another hopeful step in the right direction.

Read more: Life after al-Shabaab; a Somali city comes back to life.

Sources: al-Jazeera, NY Times, Avaaz, Guardian, Global Post, BBC, Africa News and Analysis