Several buildings in the Treaty City were spray painted overnight with derogatory slogans.
Buildings hit by the spray paint vandal included the headquarters of Irish Aid on Henry Street, and the offices of Live 95FM radio house on the Dock Road.
Offices which house HSE staff on the Dock Road, and a hair salon, were also spray painted but the slogans have been removed this morning.
At least one van was daubed with a picture of the sign for An Garda Síochána.
The slogan “F**** Media Lies” was painted on windows of the local radio station.
The slogans, “Jobs 4 dead”, and “Get a garda job?”, were painted across the offices of Irish Aid.
The motive for the graffiti is as yet unclear, a Garda spokesman said.
Gardaí are conducting door to door enquiries at businesses that were targeted.
“It was reported to us this morning and [officers] are still out and about investigating it,” said a spokesperson at Henry Street garda station.
Anyone with information can contact gardaí at Henry Street on 061-212400.