Ethiopian and Somali troops loyal to Somalia's UN-backed government on Wednesday recaptured an important city that had been occupied by Islamic rebels.

The dawn attack drove the militia fighting for the Union of Islamic Courts from Jowhar, the last key point on the northern road leading to Mogadishu, the Islamist-held stronghold and capital.

Troops loyal to Somalia's UN-backed government have recaptured Jowhar.

The successful mission put government troops in a good strategic position, opening a key route for the army to march on Mogadishu.

Government spokesman Abdirahman Dinari confirmed that his troops took Jowhar and said they would soon advance toward the agricultural village of Balad, which is the last town outside the capital. Balad is about 30 kilometres from Mogadishu.

Leaders of Islamic courts have reportedly admitted to leaving many towns.

Predominantly Christian Ethiopia sent troops for a large-scale offensive against the government's Islamic rivals on the weekend, and Ethiopian fighter jets bombed two of the country's major airports.

The White House signalled support on Tuesday for Ethiopia's military operations, noting the rise of Islamist forces posed "genuine security concerns" for Somalia's UN-recognized government.

Hundreds of people fled Jowhar in anticipation of violence. Jowhar resident Abdale Haji Ali said the approximately half a million townspeople had suffered from drought and flooding over the past two years and were now resigned to leaving.

"We do not know where to escape. We are already suffering from floods, hunger and disease," Ali said. "We are awaiting death."

While Ethiopian Prime Minister Meles Zenawi said Tuesday that his forces may soon end their offensive, Islamic fighters have said they are merely entering a "new phase" in the war. Some observers have taken that statement as an indication that terrorist attacks will be made more frequently.

With files from the Associated Press