Rail passengers bound for East Anglia faced disruption tonight on the second day of a new operator taking over the running of the region's train services.
Dutch train firm Abellio, which took over the Greater Anglia franchise only yesterday, apologised to passengers after the delays on the network.
Trains were cancelled and others faced delays due to broken-down trains, signalling problems and other faults.
A statement on the company's website read: "We would like to apologise to all customers affected by disruption to our services today.
"We are working to ensure all trains and drivers are in place for this evening's rush hour when we intend to run a normal service."
After a signalling problem at Liverpool Street, Greater Anglia reported minor delays between London and Chelmsford, Colchester, Ipswich and Norwich, on the Southend and Southminster route and on West Anglia services to Cambridge, Stansted, Hertford East, Chingford, Cheshunt and Enfield.
Until July 2014, Abellio will provide train services across Cambridgeshire, Essex, Hertfordshire, Norfolk, Suffolk and links to London.
Around the rest of Britain there appeared to be less disruption.
The Association of Train Operating Companies (Atoc) said at 12.30pm today that more than 95% of trains were operating, with more than four out of five trains getting in on time.
A spokesman said: "As has been the case over the last few days, a good service is running on the rail network today, with the overwhelming majority of trains continuing to run. Where services have been disrupted by snow and ice, we apologise to anyone who has had trouble getting to where they want to go.
"With temperatures set to remain very low in parts of the country for the next few days, train companies and Network Rail will remain on alert with staff on hand to keep the network open."
A Network Rail spokesman said: "There has been no significant disruption today as a result of weather conditions.
"We know the cold weather will be around for a little longer yet and we will continue to monitor conditions and work with the train operators to take the necessary precautions to run the best possible rail service for passengers in the coming days."