Gardaí have arrested a man following the robbery of a taxi driver at knifepoint in Ballymun last night. 

Shortly after 1.30am, Gardaí received reports a taxi driver had been threatened at knifepoint by a passenger in the Poppintree area. 

A sum of cash was stolen and the suspect fled on foot. 

The taxi driver, a man in his 40s, was not physically harmed. 

During a follow-up investigation by local Gardaí with the help of the Armed Support Unit, a man in his 20s was arrested in the Ballymun area. 

He is currently detained under Section 4 of the Criminal Justice Act, 1984, at a Garda Station in the Dublin Region.