**Two Islamist groups, previously working together in Somalia, are engaged in fierce fighting for control of the southern port of Kismayo.**At least five people are reported to have been killed and hundreds of people have fled their homes.
Al-Shabab and Hizbul Islam have been allies in battling the weak, UN-backed government, but tension has been building in Kismayo in recent weeks.
Together, the two groups control most southern and central areas.
The country has been wracked by conflict since 1991, when it last had an effective national government.
Some three million people - half the population - need food aid, while hundreds of thousands of people have fled the country.