A foreign national arrested in Athens late on Saturday with a bag containing detonators had been repeatedly reported to police in the past, according to media sources over the weekend.
Counterterrorism officers held the man, who is reportedly of Afghan origin, in a central district of the capital after a restaurant owner called police about a dispute over a bill.
A search of the man revealed a rucksack containing over half-a-dozen electronic detonators and a range of identity cards, presumed to be forgeries.
Since the initial arrest it has emerged that the man had been reported to police several times for giving an array of identities.
An investigation is continuing.