This is the fourth national strike since Bola Tinubu became president last year
Millions of Nigerians are without electricity after the national grid was shut down as part of a general strike over the rising cost of living.
The country was plunged into darkness shortly after 02:00 local time (01:00 GMT) when union members prevented operators at the country's power control rooms from working and shut down electricity substations.
Many flights have also been cancelled in the country's busiest airport in Lagos, and in the capital, Abuja, with passengers left stranded.
Unions are demanding a huge increase in the minimum wage, saying workers cannot survive on the current rate of 30,000 naira (£18; $22) a month.
The government is offering to double this but security guard Mallam Magaji Garba tells the BBC that this would not even be enough to buy a 50kg bag of rice, which he needs to feed his family each month.
The bag of rice costs 75,000 naira ($56; £44) - more than the government's proposal, even before taking other expenses into account.
“I am calling on the government to consider us and increase the minimum wage so that we can live and eat decently," says Mr Magaji, who works for the education ministry in the northern city of Kano.
“It’s not fair that we have top government officials earning millions monthly and the smallest workers earn so little and finding it difficult to feed.”
The 59-year-old said he sometimes has to walk to work as he cannot afford to pay for transport.
Nigeria's unions under the umbrella of the Nigeria Labour Congress and the Trade Union Congress are demanding the minimum wage be increased to 494,000 naira (£290; $369) which they say reflects the current economic realities.
The government says accepting these demands would cripple the economy and lead to job losses because many businesses would not be able to pay their workers and so have to close.
Schools, offices, and hospitals across the country have also been closed.
This strike is the fourth since President Bola Tinubu came to office last year.
Since then, Nigerians have been hit by a double whammy of the removal of a fuel subsidy and a collapse in the value of the naira, leading to the worst economic crisis in a generation.
The government has ended the policy of pegging the value of the naira to the US dollar, allowing it to dramatically depreciate. Whereas 10,000 naira would have bought $22 last May, it will now only purchase $6.80.
Mr Tinubu says the measures are necessary to reform the economy so it works better in the long term but in the short term, inflation has risen to nearly 34% and wages have not kept up.
