A further investigation into the incident is currently ongoing.

The Ministry said it apologized for the inconvenience caused to the public and said steps were being taken to restore power immediately, reported Sri Lanka's Daily Mirror news portal.

Power is slowly being restored in Sri Lanka with priority being given to medical and facilities and purification plants.

People were forced to depend on generators after the blackout started at around 11:00 local time (05:30 GMT) on Sunday.

A large number of internet users reacted to the power cut on X.

An X user Mario wrote on X: "A rogue monkey knocked out Sri Lanka’s entire power grid after triggering a total failure at a substation in Colombo."

Another X user Ranga wrote: "Sri Lanka begins electricity rationing for the first time in three years after the usually unreliable 900MW Norochcholai coal power station broke down on Sunday, causing a nationwide blackout. 90-minute power shedding schedule for today and tomorrow."

Jamila Husain, editor-in-chief of the Sri Lankan newspaper Daily Mirror, wrote on X: "Only in Sri Lanka can a group of monkeys fighting inside a power station cause an islandwide power outage."

In 2022, Sri Lanka had witnessed widespread blackouts during the financial crisis.