A Somali government spokesperson denied HRW's accusations that all parties are guilty in the Somalia conflict [ AFP]

Human Rights Watch (HRW) has said all the parties in Somalia's conflict have violated the rules of war and are guilty of causing civilian casualties in the fight for territorial control that is contributing to the humanitarian catastrophe there.

The New York-based group said al-Shabab, the rebel Isamist group that controls large parts of the country, was guilty of unrelenting brutality, while government troops carry out arbitrary arrests and detentions.

"All sides have used artillery in the capital Mogadishu in an unlawful manner that has caused civilian casualties," the rights group said in the report released on Sunday.

"Al-Shabab has fired mortars indiscriminately from densely populated areas and the TFG [government] and AMISOM forces have often responded in kind with indiscriminate counterattacks.

"As a result, civilians have not known where to turn for protection."

Al-Shabab withdrew from Mogadishu on August 6, saying it was a tactical move, which many fear implies resorting to suicide attacks after the fighters vowed to continue its battle against the government.

The violence in Mogadishu has hampered the distribution of aid to tens of thousands of people facing famine after fleeing to the city to escape drought in other parts of the country.

Allegations refuted

Abdirahman Omar Osman, a Somali government spokesperson, denied the rights group's accusations.

"We refute these allegations and the government is willing to meet with Human Rights Watch officials to discuss their concerns," he said in a statement.

"Reliable figures are hard to come by in Somalia which clearly shows that the information they have lacks credibility.

"On the other hand, al-Shabab is responsible for most of human rights violations that happen in Somalia."

Somalia has not had an effective government for two decades, and much of central and southern Somalia is controlled by al-Shabab, which has links to al-Qaeda.

On Monday, the United Nations warned of a cholera epidemic in the famine hit country, because of contaminated food and poor sanitation.