MOGADISHU, July 14 (Xinhua) -- At least 15 al-Shabab militants were killed on Saturday in a military operation in Somalia's southern regions barely a day after the terrorist group claimed more than 20 lives in a deadly attack.

Somali National Army (SNA) forces senior commander said Sunday the forces conducted an offensive against al-Shabab in Wanlaweyn town in Lower Shabelle region.

"Our forces advanced to take control of areas from al-Shabab extremists. We killed 15 of them and captured Yaq Buraweyne, Madah Marodi and Idow Jalad villages," SNA commander in charge of the 35th division Mohamed Abdullahi Arale said.

He added that the forces will proceed with the operations until they drive the militants out of the entire Lower Shabelle region.

Residents said they heard the sound of heavy gun fight between the militants and the army.

"A fierce battle broke out in Yaq Buraweyne village between government forces and al-Shabab militants, both sides fought for a while but government troops are now in the town and the militants withdrew from it," Jamal Ga'al , a local resident told Xinhua by phone.

Somali forces have stepped up operations on al-Shabab extremists in central and southern regions to flush the militants out of those regions.

Xinhua