Police are continuing to question a man arrested after allegedly brandishing a gun on a busy commuter train.
Major delays were caused to rush hour services on Friday evening following the alleged incident just outside Hastings in East Sussex.
A train from London to Hastings was stopped at about 1700 GMT after a passenger phoned police to say he had seen a man on board armed with a gun.
The train came to a halt near West St Leonards station, which was closed while British Transport Police officers arrested the man.
The train, the 1515 GMT South Eastern Trains service from Charing Cross, was delayed for about two hours while the incident was dealt with.
Searches carried out
All trains using the line between Hastings and Tunbridge Wells in Kent were suspended while the incident was going on.
A replacement bus service was laid on for much of the evening but trains were running as normal by Saturday morning.
It was not known whether the gun involved was real or a replica and police had not confirmed whether it had been recovered.
On Saturday searches of the train and the area near where the train was brought to a halt were due to be carried out, while the man was still being questioned.
A British Transport Police spokesman said: "The man remains in custody and will be questioned again today (Saturday).
"I am still not aware that a gun has been found but the train will be searched thoroughly today."
Passengers told the BBC people on the train had seen the gun and South Eastern Trains staff had confirmed a gun was involved in the incident.