New Delhi, July 28 -- The extremist rebels of al-Shabab seized control of the central Somali town of Mahaas on Sunday after an assault involving explosions and a ground offensive, according to witnesses.

Mahaas, in the central region of Hiraan, is located about 350 kilometers (220 miles) north of the federal capital, Mogadishu. The town is a key government outpost and a critical center in the fight against al-Shabab, which for years has been fighting to overthrow the federal government and impose Islamic law.

The rebels entered the town after federal and local forces withdrew, according to residents and local officials.

"There were multiple suicide blasts just outside the town early this morning, and heavy gunfire followed," said Ahmed...