The Secretariat of the Isoko Development Union in Oleh, a university town in Delta state was on Friday rocked by a massive explosion.
The huge blaze ripped through the facility, popularly known as Isoko House, hours after the union began its annual conference there.
Witnesses said the incident appeared to be a coordinated attack, but added that no group has claimed responsibility as at 5:00 p.m.
The union has however resumed the event with its annual award ceremony currently underway, the witness said.