Unidentified helicopter gunships on Sunday launched an attack on a target in a southern Somali town controlled by Islamist insurgent group of Al Shabaab, residents said.

The gunships fired at a house in the coastal town of Marka, 90 km south of the Somali capital Mogadishu and Islamist fighters responded by firing at the aircraft. No casualties were reported.

"The helicopters shot at a house in the town but it flew away after Islamic forces shot back at it. We do not know if the shells caused any casualties," Ali Jama, a resident in Marka, told Xinhua.

The town has been a stronghold and an important base for the Islamist group of Al Shabaab which has controlled much of southern and central Somalia for the past three years.

The Islamist group has in the past lost two important leaders, Saleh Ali Nabhan and Aden Hashi Ayro, following similar attacks in a southern town of Barawe and another in the central Somali city of Dusa Mareb.

Both attacks were claimed by the U.S. government which accused Al Shabaab of being an affiliate of Al Qaeda in the horn of Africa and of involvement in the deadly 1998 bombing of U.S. embassies in Kenya and Tanzania.

The Islamist group claimed responsibility for a deadly attack in July in the Ugandan capital Kampala which left more than 70 dead and injured dozens of others.

Troops from Uganda are part of the 6,000-strong African Union (AU) peacekeeping Mission in Somalia known as AMISOM which also comprise contingent from Burundi.

Reports from the southern town of Barawe, 200 km south of the Somali capital, also indicated that unidentified helicopters were hovering over the city while Islamist fighters were firing anti- aircraft guns at them.

Unidentified supposedly surveillance aircrafts, either manned or unmanned, are often reported to fly over Islamist controlled coastal areas in the south of the war ravaged east African nation.