Southern Gas Networks has said a gas leak which led to a road closure in Crawley Avenue has been located and engineers are now working to repair it.
The spokesman added: “Our engineers will continue working into this evening (June 11) to complete this urgent repair as quickly as possible.
“As earlier, Crawley Avenue (A23) remains closed northbound from Ifield Roundabout to Tushmore Roundabout.
“This closure extends onto part of Ifield Roundabout and a signed diversion is in place via Ifield Avenue.
“We would advise motorists to seek alternative routes where possible and allow extra time for their journeys.”