The possible political links behind Tuesday's national power grid failure that triggered a countrywide 7-8 hour long blackout are being probed, says State Minister for Power, Energy and Mineral Resources Nasrul Hamid.

The state minister made the remarks while addressing the press at the Secretariat in Dhaka on Thursday.

Referring to the recent statement made by Iqbal Hasan Mahmud Tuku, a member of BNP's standing committee, Nasrul said, "How does he [Tuku] know that such [power grid failure] incidents will happen again in the future? 

"We don't know for sure if any political links are responsible for the national grid failure. We are investigating the matter." 

Responding to queries from the reporters on why the massive power outage happened, he said that two of the distribution lines in the eastern front of the country tripped triggering a supply chain disruption which later affected the whole country.

"However, no physical damage was reported. When lines trip, it takes time to bring them up.

"That is why it took us hours to bring power back. We had to be very careful about the whole process."

After a relentless effort of three hours, the Power Grid Company of Bangladesh (PGCB) first became successful in restoring power in Kalyanpur grid sub-station and then restored power supply in the president's official residence of Bangabhaban and Prime Minister's official residence of Ganabhaban at 5pm on Tuesday.

Gradually, power supply was restored in other parts of the area and within 10:30pm, the entire country had electricity.

PGCB officials said the country's power supply demand was relatively lower at around 8500MW on Tuesday as the weather was not hot.

Bangladesh's biggest incident of national power grid failure happened on 1 November in 2014 when the entire country was without power for 17 hours.

Multiple probe bodies have been formed to investigate the matter and identify the exact cause behind the power outage.