A fault with an underground cable caused a power outage at a set of four-way traffic lights in Hastings.
UK Power Networks said engineers were called to the junction of Battle Road and Blackman Avenue, St Leonards, this morning (Friday, January 4).
Four customers also lost power supply but, according to UK Power Networks, supplies have now been restored.
A spokesman for UK Power Networks also said they believed power had been returned to the traffic lights but an eyewitness has confirmed the lights are still broken.
The witness said he has contacted East Sussex Highways in an attempt to get some temporary lights installed.
UK Power Networks added: “After a fault on an underground cable at 8.10am supplies were rerouted to customers via alternative circuits at 11.15am.
“Engineers remain on site investigating the cause.
“We apologise to customers for any inconvenience caused.”
East Sussex Highways were also called to assist.
A spokesman added: “We went out this morning to check the traffic lights and discovered it was a power issue.
“We left it with UK Power Networks.”