Rail bosses have apologised after engineering work which overran led to lengthy delays for train passengers travelling between Norwich and London.

Thousands of people were affected earlier today after improvement works at Colchester overran, with some services delayed by up to two hours. Customers had been advised not to travel unless their journey was essential, with people asked to travel to London via Cambridge if they must travel by train.

A fatality on the line in Essex in the afternoon caused more disruption.

Rail operator Greater Anglia said services between London Liverpool Street and Shenfield, Southend Vic, Colchester, Ipswich, Clacton, Braintree and Norwich had been disrupted.

A number of services were cancelled while others were running late. The fatality happened between Chadwell Heath and Romford.

The lines had re-opened by 4pm, but disruption and delays continued into the early evening.

The improvements around Colchester station aim to create more reliable services for the growing number of passengers on the Norwich to London line.

Work is due to take place on weekends up until July, but there should not have been disruption on a weekday and rail bosses have promised a 'full review' as to what went wrong.

Jamie Burles, managing director of rail operator Abellio Greater Anglia and Richard Schofield, managing director of Network Rial, issued a joint apology for the disruption. They said: 'We would like to sincerely apologise to all of our customers who were affected by the disruption to services in the Colchester area this morning and for the frustration and inconvenience this caused.

'The track replacement work was not completed on time because of problems that were encountered during the excavation and subsequent reinstatement of the track and with the on-site machinery.

'A full review is underway to understand how these problems could have been avoided, as part of our determination to avoid any repetition of the difficulties that affected services this morning.

'Network Rail engineers worked as quickly as possible to fix these problems and although services were restored through Colchester from 08.00 we recognise many passengers will have had to change their travel plans this morning.

'Subsequent alterations to services were necessary in recovering the scheduled timetable, and we made every effort to restore the normal service as soon as we could.

'Ticket restrictions have been lifted today and any customers with tickets dated for travel today (including Advance tickets) who were unable to travel, should note that these tickets will be valid tomorrow.

'Under the terms of our Passenger's Charter, customers are entitled to reimbursement up to the cost of the affected journey. Details of our delay repay scheme can be obtained from our stations and website.

'Unfortunately, a fatality incident that occurred between Chadwell Heath and Romford this afternoon has hindered our efforts to fully recover services following this morning's disruption. We are grateful for your patience and understanding while these problems are being resolved.' [View the story "'Train cancellations :(' Your anger at train delays" on Storify]