Al-Shabaab said its fighters launched an ambush attack on Somali military convoy travelling on the outskirts of Mogadishu on Tuesday.
Heavy battle flared up following the surprise assault between Somali forces and the militants that raged on for several minutes, according to the sources.
The army convoy came under attack at Jazeera area, along the coastal road connecting Mogadishu to Lower Shabelle region, south of Somalia.
There was no immediate reports of casualties as both sides remained silent on the incident which was the latest in a series of attack on the main highway in recent months.
Several senior Somali military were killed in roadside bombs in the area, which claimed by Al Shabaab, the Al-Qaeda-linked militant group in the country.