Anti-DUP graffiti painted on a wall of Royal Victoria Hospital is being treated as a sectarian hate crime.
A report had been made to police on Tuesday about the graffiti, which appeared after a pro-Palestinian slogan was removed.
Police are appealing for witnesses to come forward.
The pro-Palestinian painting on the wall had been there for six months.
Amid complaints from the DUP, Belfast Health Trust said it had been struggling to find a contractor to remove it.
The trust said several contractors had turned down the work.
