MOGADISHU, Somalia—Security services in Mogadishu have seen a new wave of defections from the Islamic extremists of al-Shabab, men who can provide valuable information or scouting services for the police, military and intelligence service.

Though some defectors have proved to be double agents who carry out close-range attacks, the government is still cooperating with defectors for the valuable insider information that the honest ones bring.

Abdirahman Omar Osman, the spokesman of the Somali president, said former al-Shabab fighters are "not easily trusted" and must go through a rehabilitation process in order to work with the government.

Abdi Aynte, the head of a think tank in Mogadishu, said there is no doubt defectors have been valuable to the government, but that stronger background checks are needed to prevent infiltration.