Another man remains in Garda custody in relation to the double stabbing on Grafton Street and Chattham Row which happened early yesterday morning.
3 people in total were injured during the attempted robberies two of them seriously.
Security Editor with the Irish Independent is Tom Brady.
He says the first man was stabbed in the chest a short time before the second assault.
"5 minutes later the gardai were alerted to another attack at nearby Chattham Row off Chattham Street and there the same two suspects had attacked a man and his girlfriend" he said.
"The man was stabbed in the back and his girlfriend was punched in the face and body and was knocked to the ground" he added.