Suspicion that a Norwegian was involved `` has been strengthened , '' security service says . The Norwegian citizen in question has not been named by authorities . Police have said they are investigating the possibility of an Islamist extremist being behind the attack and there is no evidence so far to suggest it was linked to any international terrorist group or ideology. But Trond Hugubakken , head of communications for the PST , told CNN on Saturday that the two Norwegian officers currently in Kenya are not investigating Ikrima , only the Norwegian citizen and his connections with Al-Shabaab , as they seek to establish whether he was in Kenya . The suspect is believed to have ties to a top Al-Shabaab commander , known as Ikrima .
Suspicion that a Norwegian was involved `` has been strengthened , '' security service says . The Norwegian citizen in question has not been named by authorities . Police have said they are investigating the possibility of an Islamist extremist being behind the attack and there is no evidence so far to suggest it was linked to any international terrorist group or ideology. The suspect is believed to have ties to a top Al-Shabaab commander , known as Ikrima .