Nairobi/Mogadishu - Somali parliamentarians Wednesday voted to impeach President Abdullahi Yusuf Ahmed a day after he defied parliament and appointed a new prime minister to replace Prime Minister Nur Hassan Hussein.

Yusuf on Sunday fired Hussein and his cabinet, saying Hussein was "unable to perform his duties" and that the president was obliged to act to save the country.

However, parliament on Monday voted overwhelmingly to back Hussein, who said the decision to fire him was unconstitutional.

Mogadishu-based Radio Garowe reported that 117 members of parliament had signed a document accusing Yusuf of "repeatedly violating the constitution" and ruling the country under a "system of dictatorship, unfairness and nepotism."

Neighbouring Kenya on Tuesday imposed sanctions on the president and his family, calling him an obstacle to peace.

Kenyan Foreign Minister Moses Wetangula said the sanctions would include the freezing of Yusuf's Kenyan assets and a travel ban.

Yusuf has been at loggerheads with his prime minister since the summer, when Hussein fired the Mogadishu mayor, a close ally of Yusuf.

Islamist insurgents have taken advantage of the political infighting to advance to the edge of Mogadishu.

Somalia has been embroiled in chaos ever since the 1991 ouster of dictator Mohamed Siad Barre.

The crisis has deepened since Ethiopian forces helped kick out a hardline Islamist regime in the last half of 2006, sparking a bloody insurgency that has killed over 10,000 civilians.

Hussein, who came to power last November, has accused Yusuf of trying to derail the UN-sponsored peace process between the Transitional Federal Government and opposition group the Alliance of the Re-Liberation of Somalia (ARS).

The escalation of political tensions comes as Ethiopia prepares to pull its troops out of Somalia, perhaps to be closely followed by the African Union peacekeeping force.

Al-Shabaab has refused to take part in the peace process and there are fears that it will overrun Somalia completely should the Ethiopians and AU leave.

Yusuf has admitted that the government now only controls parts of Mogadishu and the town of Baidoa.

Al-Shabaab has been implementing strict Islamic law as it takes over towns, and many are concerned of a radicalization of the population should it gain complete control.

The US says that al-Shabaab has close links to al-Qaeda, and one the alleged masterminds of the 1998 bombings of the US embassies in Kenya and Tanzania is believed to now be based in Somalia. (dpa)