Several areas of Singapore covering large swathes of the north, northeastern, east and western parts of the country experienced a complete blackout on Sept. 18, at around 1.30am.

Residents in Yishun, Sembawang, Ang Mo Kio, and as far east as Bedok and as far west as Jurong West were plunged into complete darkness for about 30 minutes before the lights came back on before 2am.

There were also reports of the blackout as far south as Tanjong Rhu.

No lights

Videos posted on Facebook showed the usually well-lit neighbourhoods engulfed in a sea of black:

Bewildered residents could be seen shining handheld lights and can be heard on the videos remarking how unusual this situation is.

Orange street lights as well as the lights in and around HDB estates had all gone out.

A video taken in Bedok Reservoir:

Wow the blackout continues... #sgBlackout pic.twitter.com/l6HPZw8ZeT

— Amanda Lee (@lamandagp) September 17, 2018

Cause unknown

It is not immediately clear what was the cause of the blackout.

SP Group said in a Facebook post at 1.42am its officers are investigating the cause of the incident:

At 2.15am, SP Group confirmed all power has been restored:At 3.54am, SP Group posted another updated with the number of people affected:Preliminary findings indicate that the disruption was due to partial loss of supply from two power generation units.

About 146,797 customers in Boon Lay, Choa Chu Kang, Clementi, Jurong, Pandan Loop, Aljunied, Geylang, Tanjong Rhu, Mountbatten, Kembangan, Bedok, East Coast, Ang Mo Kio, Bishan, Thomson, Mandai, Admiralty, Sembawang and Woodlands were affected, the power company said.

Investigations are ongoing.

Blackout 'serious' and 'extensive'

Speaker of Parliament Tan Chuan-Jin wrote on Facebook at 1.48am that there seemed to be "quite a serious and extensive blackout in a number of areas and affecting a number of blocks".

He said the hotlines are engaged and asked residents to stay calm.

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This is a developing story.

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