More than 500 homes across Weymouth and Dorchester have lost power.
A spokesman for Scottish and Southern Electricity Networks (SSEN) said: "We apologise for the loss of supply. We currently have a fault affecting the areas listed.
"Our engineers are on site working to get the power back on as quickly as they can. If you need more information, please call us on 0800 072 7282 and quote reference 'CC7117'."
The fault was reported at 4.03pm and restoration is expected at 6pm today.
The power cut is affecting homes in the DT2 and DT3 postcodes.
Engineers from Scottish and Southern Electricity Networks (SSEN) were made aware of a fault this afternoon affecting the Sutton Poyntz, Osmington and Ringstead areas.
A spokesman for Scottish and Southern Electricity Networks (SSEN) added: "This is affecting 515 properties in the area and is due to third party damage to an underground cable.
"Our engineers are on site and are expecting to restore power to the majority of customers by 6pm this evening.
“We would like to apologise to our customers for the inconvenience and thank them for their patience as our engineers work to restore their power as quickly and as safely as possible.”
There are reports that power has now been restored in Sutton Poyntz.
The are 46 known affected areas are:
DT2 8ND
DT2 8NE
DT2 8NF
DT3 4LB
DT3 6BE
DT3 6ED
DT3 6EE
DT3 6EF
DT3 6EG
DT3 6EH
DT3 6EJ
DT3 6EL
DT3 6EP
DT3 6EQ
DT3 6ER
DT3 6ES
DT3 6ET
DT3 6EU
DT3 6EW
DT3 6EX
DT3 6EY
DT3 6EZ
DT3 6HA
DT3 6HB
DT3 6HD
DT3 6HE
DT3 6HF
DT3 6HG
DT3 6HH
DT3 6HJ
DT3 6HL
DT3 6HN
DT3 6HQ
DT3 6LQ
DT3 6LS
DT3 6LT
DT3 6LU
DT3 6LW
DT3 6LX
DT3 6LY
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