The iconic Carrick-a-Rede rope bridge has been closed after "an act of vandalism overnight".
News of the closure was initially relayed on social media.
Later a National Trust statement said: "The National Trust’s iconic visitor attraction CARRICK- A-REDE Rope bridge is currently closed until further notice. During a routine safety check of the bridge before opening it was identified that the bridge was damaged overnight by an act of vandalism. This is now under investigation by the police.
"The National Trust is engaging with structural engineers to assess the damage caused, however as the safety of visitors and staff is of paramount importance, the bridge will remain closed for the foreseeable future until all necessary repairs and structural assessments have been carried out."
Max Bryant, General Manager, North Coast said: "We were very disappointed to discover that the bridge had been damaged overnight and to have to close it as a result.
"This closure is very disappointing for visitors and the local economy, as well as for the National Trust, especially leading into what will be an extremely busy weekend.”
"The National Trust would like to advise that while the bridge remains closed, the overall site is open and visitors can still come and enjoy the wildlife, coastal walks and take in the stunning views whilst enjoying refreshments in the tearoom."
Police in Coleraine have appealed for information about the incident.
Inspector Colin Reeves said: “Sometime between 6.30pm on Tuesday 23 May and 9.30am on Wednesday 24 May, a padlock on the gate which leads to the bridge was removed. The hand rope on the right hand side of the rope bridge and supporting ropes at the side of the bridge were partially cut.
“We are appealing to anyone who may have witnessed anyone acting suspiciously in the area to contact police in Coleraine on the non-emergency number 101, quoting reference number 317 24/05/17. Or, alternatively if someone would prefer to provide information without giving their details they can contact the independent charity Crimestoppers and speak to them anonymously on 0800 555 111.”