Six armed men believed to be Tanzanians were arrested over the weekend in Kenya near the Somali border.
Police say they seized several pistols and grenades during the arrest on Sunday.
Kenya’s Daily Nation newspaper says the six men, who are aged between 20 and 40, were suspected of heading to Somalia to join Al Shabaab.
Media reports are presenting conflicting details as to the exact location of the arrest, with the Daily Nation saying it took place in both Dadaab and Garissa town.
Dadaab and Garissa are over 100 kilometres apart.
Regional coordinator Mohamud Saleh says the suspects are being held in Garissa as the investigation continues.
A Tanzanian woman was also arrested in the area recently, suspected of heading to Somalia to become an Al Shabaab bride.