MOGADISHU, Oct 3, 2008 (AFP) - Islamists have imposed Sharia law on a town in southern Somalia in line with their vow to bring back Islamic theocracy to areas where they were ousted nearly two years ago, a spokesman said Friday.

'The Mujahideens of Southern Somalia', a group allied to the radical Shebab movement on Thursday named a 23-member board to enforce the law in Celwaq town, about 650 kilometres (406 miles) southwest of the capital Mogadishu.

'This administration will govern the town using laws of the Holy Koran,' its spokeman Mohamed Osmail Indhobur told AFP.

The move comes more than five weeks since Islamist fighters, accused of ties to Al-Qaeda, gained control of the southern port town of Kismayo after battles that claimed dozens of lives.

Islamists were ousted from southern Somalia early 2007 after battles with Ethiopia-backed Somali forces, ending their brief administration that had imposed Islamic law.

But they have resorted to guerrilla tactics, targeting Ethiopian, Somali and African Union peacekeepers, mainly in Mogadishu, and increasingly gaining ground.

Somalia has lacked an effective government since the 1991 ouster of president Siad Barre touched off a bloody power struggle that has defied numerous attempts to restore stability.