Maharashtra Chief Minister Uddhav Thackeray on Monday took serious cognisance of a massive power outage in the Mumbai Metropolitan Region (MMR) and ordered an immediate probe into it.

State Energy Minister Nitin Raut also said the reasons behind the technical snag that caused power failure in parts of the MMR will be probed once the electricity supply is restored.

Nitin Raut later tweeted that "Power supply to all essential services in Mumbai, Mumbai Suburbs, Kalyan, Thane, Palghar & New Mumbai have been restored".

After ordering a probe, the CM held a meeting at his official residence in afternoon which was attended by state chief Secretary Sanjay Kumar and representatives of power supplying companies like BEST, Tata and Adani.

Nitin Raut and Minister of State for Energy Prajakt Tanpure attended the meeting via video conferencing.

Earlier in the day, an official statement said Thackeray took serious note of the power outage and ordered an immediate probe into it.

Thackeray instructed Brihanmumbai Municipal Corporation (BMC) Commissioner Iqbal Singh Chahal to make alternate arrangements so that power supply to hospitals is intact, the statement said.

He also directed the state chief secretary to ensure that the control rooms and fire brigade are on alert to see there are no other mishaps due to power outage, it said.

The chief minister had asked officials to coordinate with the railway administration to help passengers after the suburban local train services were hit by the power failure, the statement said.

In morning, a rare citywide power outage paralysed Mumbai, halting local train services, trapping people in lifts and disrupting work from home adopted by millions during the ongoing pandemic.

Power restoration efforts began on "war footing" and pocket-wise resumption in supply was started around 12 noon onwards, nearly two hours after the outage.