Services are suspended on Greater Anglia between Broxbourne and Hertford East, and between Cheshunt and Cambridge due to overhead line problems. There are no replacement buses available and it is not clear when services will resume.
Elsewhere there are replacement bus services running on between Ipswich and Manningtree and between Manningtree and Liverpool Street.
There are also no services between Witham and Braintree due to a fallen tree on the line.
And services are suspended on Greater Anglia between Sudbury (Suffolk) and Marks Tey due to overhead line problems.
More top news
With harmful pollutants at record levels the Mayor of London's campaign aims to highlight the impact air quality can have on health.
A firework was shot into a London bus sending frightened passengers running with fear.
Abdul Samad, 28, was stabbed outside his family home in Little Venice last night and died an hour later in hospital.