A man has been arrested by Gardai investigating the death of a man in Dublin city centre.

The victim is thought to have been aged in his 20s and was decapitated after falling in front of a bus during a row at the junction of Nassau Street and Dawson Street at around 5:45pm yesterday.

The man killed was not carrying any identification and his injuries were so catastrophic Gardai are having difficulty establishing who he is. 

Gardai have trawled through CCTV footage of the incident and this afternoon a 28 year-old suspect was arrested.

He is being questioned at Pearse Street Garda Station under Section 4 of the Criminal Justice Act.

The man can be questioned for up to 24 hours. 

Fatal incident raised in the Dail

Transport Minister Leo Varadkar has extended his sympathies in the Dáil.  

"I really want to extend my sympathy to that man and also to his family" he said.

"And also particularly to the bus driver who was involved in the incident - and I think it must be very traumatic and very shocking for him as to what happened and he certainly has my sympathies as well" he added.