Members of Sinn Fein Republican Youth have been blamed for placing anti-Syrian airstrike posters on the office of DUP Assembly member William Humphrey.
The posters object to the UK Parliament's decision to vote for airstrikes in Syria.
Alongside a silhouette image of women and children running from bombs dropping from the sky are statistics of what the cost of an airstrike could otherwise pay for and the words: "And you dare to call me a terrorist".
Logos for the Mairead Farrell Republican Youth Committee and Sinn Fein Republic Youth are at the bottom of the posters.
North Belfast MLA William Humphrey said: "It is deeply ironic for any part of Sinn Fein to accuse anyone of supporting terrorism, given their persistent support of murderous IRA terrorism.
"They are in no position to lecture anyone, given the reckless actions of the IRA which killed hundreds of innocent people and maimed thousands during the so-called Troubles.
"I am grateful to the constituents who noticed people sticking these posters on my constituency office and who recorded details of what occurred.
"That information has now been passed on to the police to assist with their investigation."
The DUP representative added: "On Wednesday night Members of Parliament had to make the most difficult of decisions, to extend the area of RAF airstrikes against ISIL into Syria.
"However, it must be remembered that the first duty of any government is to protect its citizens and it is clear that ISIL is a terrorist threat against our nation which must be confronted and degraded. I salute our brave servicemen and women who are risking their lives in seeking to protect us from this evil scourge of terrorism.”
Sinn Fein has been approached for a comment.