Signalling problems marred the resumption of full rail services through Salisbury following a crash involving two trains.

The line between the Wiltshire city and Andover reopened on Tuesday, 16 days after the collision between South Western Railway (SWR) and Great Western Railway (GWR) trains.

But several services were cancelled or delayed by up to an hour while a signalling fault was fixed.

The issue was reported at around 11.30am, and disruption to SWR and GWR trains was expected to continue until 7pm.

Network Rail said: “We’re sorry for the disruption in the Salisbury area at the moment, which is affecting SWR and GWR passengers.

“Engineers are on site and investigating as we speak.”

A major project was carried out to reopen the line following the crash.

This included laying more than 900 metres of new track, replaced three sets of points, moveable rails that allow trains to switch from one track to another, and installing almost 1,500 sleepers, which hold rails in the correct position.

Test trains ran on the line before passenger services resumed on Tuesday morning.

Investigators believe the crash on October 31 happened after a SWR train approaching Salisbury’s Fisherton Tunnel failed to stop at a red signal despite braking, due to its wheels slipping on the rails.

The Rail Accident Investigation Branch said this led to it travelling 220 metres past the signal before smashing into the side of a GWR train at the point where the tracks they were on merged.

Both trains derailed and travelled into the tunnel before coming to a standstill.

The SWR train was driven by Robin Tandy, 74, who suffered what police described as “life-changing injuries”.

Thirteen passengers were treated in hospital for minor injuries.