The outage also discomforted citizens in the humid autumn weather.
"It is almost impossible to stay at home with kids in this suffocating hot temperature," Shahnaj Tanvir, a housewife in Dhaka's Malibagh area, said.
Bangladesh Prime Minister Sheikh Hasina had earlier assured to supply uninterrupted electricity, but to no avail.
The country's economic growth has been threatened by power shortages as daily blackouts are compounding the woes of the main textile industry, which earns most of the country's foreign currency. Bangladesh is the world's second-largest garment exporter after China.
"The country must ensure uninterrupted power supply to continue its impressive economic growth and to attract more foreign investment," said Abu Ahmed, a former economics professor at Dhaka University.
In a report last month, the Asian Development Bank said Bangladesh's economic growth would slow to 6.6% from its previous forecast of 7.1% in the current fiscal year.
