JOHOR BARU, Dec 6 — Tenaga Nasional Berhad (TNB) said that the electricity power outage that caused a blackout at the Sultan Iskandar Building’s (BSI) Customs, Immigration and Quarantine (CIQ) Complex here was caused by damage to a generator set.

In a statement, the utility provider said the issue was due to recurring damage to the generator set that was used to provide temporary electricity supply to the CIQ building.

"TNB has carried out work stoppages for a scheduled maintenance and installation work at the Gerbang Perdana 33/11kV main distribution substation (PPU) here starting 8pm yesterday until early this morning.

"When the work was carried out, temporary electricity supply was supplied through 10 generators belonging to BSI so that there were no electricity supply interruptions during that period.

"Investigation found that there was repeated damage to one of the generators in question, which was used to provide temporary supply and had resulted in a supply disruption at the premises of the CIQ building,” it said.

TNB said that the electricity supply to BSI was fully restored at 9.13am morning after more than seven hours of total power shutdown that started at 2am.

Meanwhile, TNB added that it was aware of the proposal by the Johor state government to consider alternative electricity sources to further strengthen the power supply system to the CIQ.

"TNB also works closely with BSI’s management to ensure the safety and stability of power supply to the premises and its surroundings,” read the statement.

Earlier, Johor works, transportation, and infrastructure committee chairman Mohamad Fazli Mohamad Salleh said the government has also proposed to Tenaga Nasional Bhd (TNB) to bring in an additional two external power supply systems to BSI.

He was reported to have said the additional power supply is part of the long-term solution following last night’s blackout.

Last night, the hours-long power outage at Johor’s mainland checkpoint had disrupted travel between Malaysia and Singapore.

Long queues were reported at the immigration counters and heavy traffic on the Johor Causeway.