Eighteen people have been killed in gun battles between rival militias fighting for control of the Somali port city of Kismayo.

According to Kismayo residents, 13 people were killed on Saturday and five died on Friday.

"The Ras Kamboni militia now controls this part of the city," said Bile Nur, a resident of Kismayo's Calanleey district.

"Residents are burying the dead of the militia driven out, while Ras Kamboni are burying theirs," he added.

Local elder Nur Ibrahim said there is not much hope for a negotiated end to the fighting. "We hope fighting will cease. Only the man with the most weapons will remain in power."

African Union troops are currently in charge of security in the lucrative port of Kismayo and its fertile hinterlands.

In October 2012, Kenyan troops backed by Ras Kamboni militiamen, captured the city from al-Shabab fighters.

On Saturday, a senior al-Shabab official in Kismayo said Kenya was responsible for the latest bloodshed.

“The resurgence of tribal hostility in Kismayo is a result of the Kenyan invasion of the city and the Kenyan government will be held fully responsible for every drop of blood," Sheikh Xudayfa Abdirahman stated.

Somalia has not had an effective central government since 1991, when warlords overthrew former dictator Mohamed Siad Barre.

However, MPs meeting in Mogadishu elected Hassan Sheikh Mohamud as the new president of Somalia with a big majority in September 2012.

The weak Western-backed government in Mogadishu has been battling al-Shabab fighters for more than five years and is propped up by a 10,000-strong African Union force from Uganda, Burundi, Djibouti, and Kenya.