By Feisal Omar and Abdi Sheikh

MOGADISHU Oct 26 (Reuters) - Islamist militant group al Shabaab took control on Wednesday of a town in southern Somalia after African Union peacekeepers and government troops abandoned it, residents and the group said.

Ethiopian troops in the peacekeeping force known as AMISOM, government soldiers and al Shabaab have fought many times this year over control of Tiyeeglow district. When troops secured it, al Shabaab has strived to isolate it.

Al Shabaab said it took Tiyeeglow district near the Ethiopian border after the Ethiopian and Somali soldiers moved to Hudur, the Bakool region's capital.

Tiyeeglow district is important because it links Bakool to Hiiran region, where al Shabaab have taken over three towns this month.

"Now we see hundreds of al Shabaab fighters and its banner flapping in the centre of the town. The Ethiopian and Somali troops moved out yesterday and last night," local elder Maamad Nuur told Reuters.

"There is much fear."

Abdiasis Abu Musab, al Shabaab's military operation spokesman, confirmed the take over the town.

"We entered Tiyeeglow district the minute the Ethiopian troops left early this morning. We now fully control it," he said.

Ethiopian and Somali government officials were not available to comment.

Al Qaeda-linked al Shabaab, which once ruled much of Somalia, wants to topple the Western-backed government in Mogadishu and drive out AMISOM peacekeepers also made up of soldiers from Kenya, Djibouti, Uganda and other African nations.

In a sign of their capability to strike, the group rammed a military base with a suicide truck bomb, shot dead an intelligence officer and killed 12 people in a Kenyan border town in a series of strikes over 24 hours to Tuesday. (Writing by George Obulutsa; Editing by Angus MacSwan)