The Power Grid Company of Bangladesh (PGCB) has formed a 5-member inquiry committee to investigate the reason behind the grid failure on Tuesday that triggered a countrywide blackout for hours.

Yakub Elahi Chowdhury, executive director of the organization, will lead the investigation, said its public relations officer Badruddoza Sumon.

National power transmission grid failed at 2:05 pm - causing blackouts across Bangladesh, except some parts of the north.

Power supply was restored in some parts of Dhaka city under Maniknagar and Hasnabad grid substations and also a good number of districts under Sylhet, Chattagram and Mymensingh by 7 pm.

According to officials of the PGCB, it could take two more hours to get electricity supply restored in all the areas of Dhaka and Narayanganj cities, along with the remaining other districts.

"We hope normalcy in power supply will be fully back by 10 pm," Sumon told UNB.

He said the districts where power supply was fully restored by 7 pm include Tangail, Kishorganj, Mymensingh, Jamalpur, Manikganj, and all districts in Chattagram and Sylhet divisions.

Earlier, after the national power grid failure earlier today, power supply was restored in some Dhaka areas, including president and prime minister's official residences, around 5pm.

State Minister for Power, Energy and Mineral Resources Nasrul Hamid had hoped that power supply may fully be restored by 7 pm.