Further trains would be delayed, cancelled or diverted via Seven Sisters, a spokesperson added.
London Fire Brigade said 14 engines were being used to tackle a grass fire, near Lea Road in Waltham Abbey, which is close by.
It is unclear whether this is a separate blaze and the BBC has asked the service how many incidents it is dealing with in the area.
Greater Anglia also said Network Rail officers were on site, “working as quickly as possible” to help restore train services to normal.
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