Nairobi/Mogadishu  - Pro-government militiamen have seized control of an insurgent-controlled town in Somalia as the government pushes back against Islamist rebels trying to topple the Western- backed president, reports said Wednesday.

Al-Shabaab, which the US says is linked to al-Qaeda, and its allies Hizbul Islam are attempting to oust President Sheikh Sharif Sheikh Ahmed, a former ally who came to power earlier this year as part of a United Nations-backed peace process.

A military official told Radio Shabelle that pro-government forces had seized the town of Luuq, which lies in Gedo district near the border of Ethiopia, from Hizbul Islam on Tuesday.

Hizbul Islam fighters reportedly left without putting up any resistance. On Monday, fighters from Ahlu Sunna Waljamaca - an Islamist militia backing the government - forced al-Shabaab out of Bulahawa, also in Gedo.

An estimated 18,000 Somalis have died and over a million have been displaced by the insurgency, which began in early 2007 following an invasion by neighbouring Ethiopia.

Ethiopia withdrew in January from Somalia, which has been embroiled in chaos since the 1991 ouster of dictator Mohamed Siad Barre.

However, an insurgent spokesman told Shabelle that Ethiopian troops were backing the government offensive.

The government was nearly brought to its knees in May, when the insurgents launched a series of fierce attacks in the capital Mogadishu and other towns.

Neighbouring Eritrea was accused of arming the insurgents as part of a proxy conflict with Eritrea.

The government has survived, in part due to 40 tonnes of arms and ammunition provided by the US.

US Secretary of State Hillary Rodham Clinton promised to send more assistance during a recent meeting with Sheikh Sharif in the Kenyan capital Nairobi.

The US is particularly concerned that al-Shabaab could launch more terror attacks on US targets in the region and beyond if it gains control of Somalia.

Al-Qaeda bombed the US embassies in Nairobi and Dar es Salaam, Tanzania, in 1998, killing over 200 people.(dpa)