A huge hole has been discovered under Belfast's Ravenhill Road.
Workers carrying out sewer improvements for NI Water found the "large void" on Monday under the road at the Park Road junction, where Ormeau Golf Club is located.
Ravenhill Road had been operating with one lane under temporary traffic signals during the roadworks - but it will now be shut entirely while the hole is filled.
NI Water's contractor will carry out the emergency work to ensure the road is structurally sound.
A statement said: "During the course of a major sewer rehabilitation project in the Park Road/Ravenhill Road area, contractors working on behalf of NI Water have discovered a significant void.
"NI Water is liaising with Road Service colleagues in relation to the matter. A temporary closure of the road will be required to allow work to address the situation to be completed. Further details will be carried on the Trafficwatchni website and updates will also be carried on the niwater.com.
"Due to the unforseen nature of the problem the extent of the work required to repair the road fully is not yet clear and as such the longevity of this closure has not been established."
Trafficwatchni says the work to fill the void will be completed as quickly as possible by tomorrow (Tuesday), however until such times traffic will be diverted onto the Ormeau Road at the Rosetta roundabout (city bound) and the Ormeau Embankment (country bound) with the Ravenhill Road fully closed between Ravenhill Park and South Parade.