Railtrack last night allayed fears over safety after the discovery of a broken rail on the East Coast Mainline.

The broken rail, discovered at 9.18am today by workers from maintenance company Jarvis, caused services to be disrupted on the route which links London, the North-East and Scotland.

Four London-bound GNER trains were held up just short of the fault at Connington, near Peterborough, before being allowed to continue their journey at a reduced speed.

Repair work led to a section of the track being closed with one of two northbound lines being used for London-bound trains to allow southbound services to continue.

Last night Railtrack said there was "no question" of the broken rail causing a derailment.

It was a broken rail that caused a GNER train to crash at Hatfield in October 2000, in an accident that claimed four lives.

A Railtrack spokeswoman said: ''A track maintenance patrol spotted a rail that was cracked.

"Rails can break and crack within 24 hours and we have an on-going programme to spot such things.

"We were not talking here about a huge chunk being sheared off but a very fine crack."

It was thought that repair work would continue into the night, but work was completed by lunchtime with the track re-opening at about 1.15pm.

Knock-on delays to services continued throughout the day although trains were back running as normal by the evening.

Some East Coast services had already been disrupted by the collapse of some overhead electric wires south of Berwick, Northumberland, at about 9am yesterday.

Phil Bustard, of GNER, said: "There were two periods of disruption which added to journey times but things were pretty much back to normal by evening rush hour.

"It is good that Railtrack is being pro-active in matters such as this by spotting problems and sorting them pretty quickly."

Earlier this year The Northern Echo revealed a number of concerns about maintenance on the East Coast Mainline.

These included nuts on a set of points near Darlington railway station possibly being deliberately tampered with and fears over trackside rubbish obstructing trains.