Rail services from Gatwick Airport towards Brighton are delayed this morning (May 21).
Govia Thameslink Railway (GTR), which operates Southern and Thameslink services, said: “We were advised that the 9.14am Gatwick Express service from London Victoria to Brighton, had a passenger alarm activated outside of Gatwick Airport. This blocked some of the lines towards Brighton and Horsham, and created a queue of services behind it, while the alarm was investigated.
“Services are on the move at Gatwick Airport now.
“As some trains were held while the alarm activation was investigated, there will be some short notice alterations to trains to recover services.”
It said services will be subject to delays until midday.