Loyalists have been blamed for stealing tricolours from Lifford Bridge in advance of the National Hunger Strike Commemoration in Strabane this weekend.
Donegal Sinn Féin Councillor Gary Doherty and his Strabane party colleague, Councillor Michaela Boyle, in a joint statement, said: "In preparation for Sunday's Hunger Strike Commemoration tricolours were erected along Lifford Bridge last night as well as along other parts of the route the parade will follow.
"In the early hours of this morning and under the cover of darkness, a group loyalists ripped down and stole as many flags as they could before being challenged by local people who were then subjected to sectarian abuse by those involved as they made off in two cars."
The Sinn Féin representatives said the vandalism would only strengthen their resolve to pay tribute to the ten men who died in the 1981 IRA/INLA hunger strike.
"Everyone has the right to remember their dead with dignity and pride and it is sad that these loyalists should be so 'small minded' as to engage in such futile acts.
"These actions will only serve to strengthen the resolve of republicans to pay a fitting tribute to the memory of the hunger strikers this weekend," they said.