The night operation in Barwaqo and sections of Warda Nabada district saw many young people spend the night in police cells.

Police said hundreds of young people who were taken to custody will be questioned with a view to getting more information from them.

Security officials believe armed groups have used residential areas as bases to prepare attacks and then mingle with residents in urban areas to carry them out.

A-Shabaab carried out a deadly attack at the Ministry of Labour Saturday killing at least 15 people including deputy Labour minister Saqar Abdalla.