National Directorate of Security spokesman Hasib Sediqi said today that the militants affiliated with the Feday-e-Mahaz group were detained in Kabul last week along with a time bomb, two pistols and a silencer.
He says the group had been planning to carry out an attack in the Afghan capital.
Feday-e-Mahaz claimed responsibility for last year's killing of Swedish Radio correspondent Nils Horner while he was reporting on Afghanistan's election on a street in Kabul.