The ugly incident happened after a gas cylinder went up in flames, which left panic in the air and many people running to safety.
The banking hall of the country’s apex financial institution was left shattered after the blast took place at about 11am.
Security officials had a tough time condoning off the area, while fire fighters tried to put the inferno under control.
Speaking on the incident, Cross River State Commissioner of Police, Henry Fadairo said, “The team of expert handling the situation confirmed to me that 18 persons were injured while two others are said to be in a critical situation.
“The explosion was caused by gas cylinders in the CBN. It is not a bomb blast as it is already being speculated in some corners.
“The police in company of the Navy, Army, FRSC and the Civil Defence were on ground to help the state Fire Service to bring the situation under control.
“We also assisted the medical team to convey the victims to the University of Calabar Teaching Hospital where they are currently being attended to.”
On his part, Director-General of State Emergency Management Agency, John Inaku, described the disaster as unfortunate.