( CNN ) -- An Islamic militia took over two strategic towns in Somalia Tuesday in a territory grab by the strengthening insurgency , a regional commander told CNN . Islamist fighters from Al-Shabaab group in Somalia display their flag . The al-Shabaab militia seized the cities of Bulo Marer and Quryoley from the U.N.-backed government and its Ethiopian allies . The move gives the group a strategic base in central Somalia , where it also controls Kismayo , the country 's third-largest city . Al-Shabaab is an offshoot of an Islamic party that ruled much of the country in the second half of 2006 and aims to impose Islamic sharia law in Somalia . Nur Shekoy Jabril , the commander of government forces in Quryoley , said his troops withdrew from the two towns after they faced being overwhelmed by the al-Shabaab force . He said al-Shabaab forces were moving toward Merka , another major town in the region where the Untied Nations uses an air strip to fly in supplies for the World Food Programme . Somalia , which has not had a functioning government since 1991 , is in the throes of an Islamic insurgency which is battling for control of the country and the ouster of Ethiopian forces . A cease-fire between the some of the Islamic fighters and the Somali transitional government takes effect on Wednesday . The agreement was brokered by the United Nations and the African Union and signed late last month in Djibouti . It calls for Ethiopian forces -- who are supporting the transitional government forces -- to withdraw starting on November 21 . It is unclear if the cease-fire will hold as it has already been rejected by Al Shabaab . Somalia 's lawlessness also spilled onto the seas off the Horn of Africa , where international vessels are routinely hijacked by suspected Somali pirates who demand large ransoms .
The al-Shabaab militia seized the cities of Bulo Marer and Quryoley . The move gives it a strategic base in central Somalia . Al-Shabaab an offshoot of Islamic party that ruled in Somalia for much of 2006 . The group aims to impose Islamic sharia law in Somalia .