MOGADISHU, Sept. 28 (Xinhua) -- Somali security forces on Friday confirmed the arrest of an al-Shabab militant, believed to be a bomb expert, in an operation conducted south of Mogadishu.

The National Intelligence and Security Agency (NISA) said there were no casualties during the operation that happened on Thursday night.

"National Intelligence and Security Agency conducted a carefully and well planned security operation that took several hours at Ex-control in Mogadishu overnight and arrested al-Shabab bomb expert, no casualties so far on our side," it said in a statement.

There was no immediate comment from the al-Qaida allied terror group on the arrest of its bomb expert.

Meanwhile, Somali National Army (SNA) confirmed that its forces killed 16 al-Shabab militants in an operation in Jilib Marka, south of Mogadishu, on Thursday.

Omar Dhere, commander of 12th April Battalion of SNA, told a military-run radio that the forces killed an Afghan fighter identified as Nasir Al-Jabiri during a fierce fighting with the insurgents near the coastal town of Marka, about 90 km south of Mogadishu.

The Somali militants have recently intensified assassinations in the capital, Mogadishu, particularly in the last two months. Several government officials and soldiers have been killed in the attacks.

The latest arrest came amid heightened security in the Somali capital following the deployment of more security forces and erection of security roadblocks along key roads.