A DISRUPTION to rail services in the South West caused by the discovery of cracks in some high speed trains is expected to continue into next week, a rail industry group has warned.

Robert Nisbet, of the Rail Delivery Group, said initial inspections of 183 trains taken out of service on Saturday should conclude by the end of Sunday, but he warned that disruption was expected to "carry on for a few days".

Two of the UK’s busiest rail firms are warning people not to travel on Sunday.

On Saturday, Hitachi 800 trains operated by Great Western Railway and London North Eastern Railway trains were taken out of service for safety inspections.

Hitachi has apologised and said it was investigating the issue.

Mr Nisbet, whose organisation represents train operators and Network rail, apologised to anyone affected by the disruption.

He said rail firms were running as many services as possible, including rail replacement services, in addition to laying on extra staff at affected stations, relaxing ticket acceptance rules and offering compensation for delays.

Mr Nisbet told BBC Breakfast that it was "gratifying to see the speed" at which initial inspections were taking place. He said he understood that Hitachi engineers would complete these inspections by the end of Sunday.

But he cautioned that he was still "expecting some disruption to carry on for a few days".

He said: "It’s impossible for me to say exactly how long that is going to take, we are obviously going through this as quickly as possible but we don’t want to rush it.

"We want to be sure that all of those trains are thoroughly inspected and cleared and are put into service when things are ready.

"But there may well be a knock-on effect for some of those timetables into next week."

On Saturday railway minister Chris Heaton-Harris warned Great Western Railway services in particular were likely to face continued disruption.

Andrew Barr, CEO of Hitachi Rail, said the decision to withdraw the trains had been taken because of cracks found on the metal that linked the train’s body with the underside of the train- known as the bogie.

All high-speed Great Western Railway services between London, Bristol, Cardiff and Penzance were cancelled on Saturday.

Local services are running, but they are expected to be very busy and rail replacement services were are limited.

"Customers are advised not to travel on Sunday, 9 May and refunds will be provided," Great Western Railway said.

"Once trains have been checked and cleared, we hope to be able to release them back into service as soon as possible."

The company earlier said cracks were detected on "more than one" Hitachi 800 train, so all 93 in its fleet were being inspected as a precaution.