The Metro system has been running for more than 20 years

The line between the Haymarket and the Regent Centre, in Newcastle, was affected by the closure on Sunday.

All services on the affected line were suspended, and a replacement bus service run instead.

Ken MacKay, director of Metro for operator Nexus, says that more repair work will be likely over the next few years

He said: "One of the things that is unique about the Tyne and Wear Metro is its age.

"We are in that phase where things do have to be replaced.

"What we are seeing now is the first phase of that and over the next few years we will be doing more of this work than we have done in the past.

"It is simply a necessary facet of keeping the Metro going."