Somali national army, along with Jubbaland and Kenyan troops were reported to have started a military movement in parts of the country's southern Lower Jubba region, according to the residents.
The allied forces are conducting joint operation in the areas around Kismayo city, the interim administrative capital of Jubbaland in a bid to flush out Al-Shabaab from the remaining pockets.
The move came after Al-Shabaab has carried out a deadly truck bombing and gun attack on a military base in Sanguni, a small town situated some 50Km north of Kismayo city, killing 27 soldiers on Monday.
Local residents said tension remain high since Monday's Al-Shabaab attack as the joint forces are preparing a final offensive against the militants trying to seize control of the areas near Kismayo.
Since Kenyan army crossed into southern Somalia in 2011, Al-Shabaab has stepped up attacks in the Jubba and Gedo regions as well as cross border raids targeting Kenyan Police in northeastern region.