Trains are running at a reduced speed through Essex because of urgent repairs to a bridge near Witham.
Passengers were subjected to long delays and disruption on Abellio Greater Anglia trains in Essex and Suffolk on the weekend because of the repairs.
Network Rail said engineers worked overnight to fix the problems.
A spokesperson for Abellio Greater Anglia said: "Because of damage to a bridge between Witham and Hatfield Peverel, trains are running at reduced speed in this area, with some minor delays to services.
"We apologise to customers for any inconvenience caused. The advertised timetable is currently in operation and customers should check for service alterations via our website, or at stations."
A spokesman for Network Rail said: "Damage to the railway bridge at Blunts Hall in Witham was discovered on Sunday morning.
"Following temporary repairs which took place throughout Sunday and on Sunday night, both lines have reopened this morning (Monday July 6) with a 20mph temporary speed limit in place over the bridge.
"Engineers are still on site carrying out further inspections to see if the speed limit over the bridge can be raised. In the meantime, journeys through the affected area are taking a few minutes longer than normal.
"It is not yet clear what caused the damage to the bridge and we continue to investigate how it happened. Further repairs will need to be carried out to the brickwork."