A power outage at the venue of a National Citizen Party (NCP) rally in Savar last night was caused by a short circuit in a transformer, not by an intentional power cut, according to Dhaka Palli Bidyut Samity-3.

Md Mamun Or Rashid, general manager of the utility, told The Daily Star that a transformer connected to the same feeder developed an earth fault and caught fire, causing the feeder to trip automatically and disrupting power supply from the substation.

"The system recorded the incident as a phase-to-ground fault, and all relevant data have been preserved," he said.

The explanation comes after a power outage at the rally venue shortly before NCP leaders took the stage fuelled speculation, particularly after a crude bomb exploded during the programme, injuring at least four people.

According to Mamun, locals reported the outage around 24 minutes later, after which electricity was restored. Officials who inspected the site today found the fault still existed in the transformer located in nearby Bhagalpur.

He also said the utility had not been informed in advance about the NCP rally and that none of the organisers contacted the authorities after the outage to seek an urgent restoration of power.

Mamun said police, the Detective Branch (DB) and the National Security Intelligence (NSI) had reviewed the utility's records and were satisfied with the findings.