A radical Islamic group seized another Somali port town Saturday, consolidating its control over a southwestern region that borders the Somali capital.

Amin Adan, a resident of the port town of Barawe, said that fighters of al-Shabab took control without a fight because the government's allies left as soon as they heard the fighters were on their way.

"We don't know whether it is a tactical retreat," Adan told The Associated Press by phone from Barawe, 110 miles southwest of Mogadishu. Barawe is near Merka, a key port town with an airstrip that al-Shabab seized earlier this week; both are in the region of Lower Shabelle, which surrounds Mogadishu.

The steady and seemingly uncontested rise in recent months of al-Shabab — meaning The Youth — which the United States considers a terrorist organization, is a far cry from the situation in late 2006, when Somalia's U.N.-backed government rolled into Mogadishu supported by powerful Ethiopian troops and drove out radical Islamists intent on ruling by strict Shariah law.

The past two years have been a bloodbath as the Islamic fighters launched a vicious insurgency, mainly in Mogadishu, that has killed thousands of civilians and sent an estimated half of the capital's 2 million people fleeing from near-daily roadside bombings and remote-controlled explosions.

The fighters have seized most of southern Somalia — advancing to within 10 miles of the capital on Wednesday.

In Mogadishu, where the government is still nominally in control, Shabab fighters carry out public punishments such as lashings and stonings, conduct training exercises and present themselves as an alternative government.

Despite their advances, however, the Islamists are suffering internal divisions. Al-Shabab — considered a terror group because its leaders are allegedly linked to Al Qaeda — controls the most territory. But more moderate fighters from groups including the Council of Islamic Courts have also taken towns.

The U.S. worries that Somalia could be a terrorist breeding ground, particularly since Osama bin Laden declared his support for the Islamists. It accuses al-Shabab of harboring the Al Qaeda-linked terrorists who allegedly blew up the U.S. embassies in Kenya and Tanzania in 1998, killing more than 230 people.

Somali government forces acknowledge they are struggling but say that they will get all of Somalia under control. They offer no details, however.

Presidential spokesman Hussein Mohamed Mohamud said that, with the help of Ethiopian troops, the government is "trying to retake all the regions" under the control of al-Shabab.