A Norfolk man has said he narrowly escaped injury after part of a railway track flew off the line and smashed through his office window.

Patrick Kibble said the six-inch metal fixing missed him by inches after shattering the window of his office in Diss, which overlooks the main London to Norwich line.

The 33-year-old finance director, who works for electronics firm Barric, was showered with glass.

Railtrack has now launched an investigation to discover how the metal clip flew off the track.

It was a good job I was not sitting back in my seat, or that no-one was standing behind me

Patrick Kibble

The incident happened on Wednesday when a London-bound Anglia Railways train passed Mr Kibble's office.

Mr Kibble said: "It came hurtling through window, obviously all the glass was over myself and the next three desks.

"It hit the wall behind me and made a chunk in the brick about the size of a 50p piece, hit the wooden unit next to me and dented that.

"Fortunately I was leaning forward - it was a good job I was not sitting back in my seat, or that no-one was standing behind me."

'Unusual events'

A spokeswoman for Railtrack said the company was "very concerned" about the incident.

"This seems to be an extremely unusual set of events.

"We are very concerned about it and have launched an investigation."

After the incident, trains on the line were slowed to 20mph so initial investigations could be carried out, but the normal service was later resumed.

Peter Meades from Anglia Rail said: "It is obviously of great concern to us as a train operator.

"Having said that, I'm pleased in this instance that Railtrack acted very quickly. They immediately had people on site and launched an investigation to find out how on earth this could have happened."