The incident happened on the popular Milikin Hill road, which led to Ngwo town, in Enugu.
It was learnt that the commercial bus just left Enugu New Market, located a few kilometres from Milikin Hill, when armed civil defence officials asked the driver to stop.
The Enugu headquarters of the NSCDC is located near New Market.
The driver reportedly refused to stop, and sped away as the NSCDC men chased the bus with a Hilux van.
It was also gathered that some officers of the security agency boarded a commercial tricycle to join in the chase along the narrow, winding Millikin Hill Road, which is bordered on both sides by a deep valley.
Eye witnesses disclosed that as the commercial bus was getting to the end of the road, the civil defence officers opened fire on the vehicle, causing the driver to veer off the road and crash into the valley.
The vehicle burst into flames instantly, eye witnesses said.
Reports of the development led to protests by commercial bus drivers and other members of the public, particularly natives of Ngwo town, which is believed to be where the passengers were headed before they met the tragic end.
Some of the drivers and youths attempted to protest at the office of the NSCDC around New Market, but heavily armed men of the civil defence outfit repelled the planned protest at their headquarters by barricading the road leading to the office, and shooting into the air to scare away those who ventured to come closer.
Some commercial bus drivers who spoke with our correspondent during the protest said the civil defence men shot at their vehicles when they approached the building.
Our correspondent was shown some commercial transit buses with shattered windscreens and other glasses, with the drivers claiming it was the result of bullets fired by the NSDC officers.
At the scene of the crash on Millikin Hill, our correspondent observed that the commercial bus was totally burnt down.
The burnt remains of a passenger, one of the victims of the incident, was seen trapped under the vehicle, which was lying on its back inside the valley.
An official of the Federal Road Safety Corps, who was at the scene of the crash, informed our correspondent that the remains of some other passengers who died in the crash were moved to an undisclosed hospital morgue.
But the road safety official and scores of policemen at the venue could not confirm the number of casualties.
No personnel of the NSCDC was at the scene of the incident when our correspondent visited the place.
There were reports that the civil defence personnel involved in the incident have been taken into custody, but the report was not confirmed.
A towing van was eventually brought to lift the commercial vehicle, after which the trapped, burnt remains of the last passenger was recovered and moved by an ambulance to the morgue of Eastern Nigeria Medical Center, Enugu.
Police sources informed our correspondent that a young girl, said to be the sole survivor of the crash, was taken to the office of the Enugu State Commissioner of Police.
The said young girl is expected to make a statement as part of investigations into the incident.
The policemen at the scene of the incident told journalists to come to the headquarters of the Enugu State Police Command to speak with the girl; but the Commissioner of Police, Enugu State, Mohammed Danmallam, who later arrived at the venue of the protest, said the girl has been hopitalised and was not yet disposed to talk.
Danmallam assured that the incident would be investigated.
He said investigations have commenced.
The police commissioner also disclosed that arrests have already been made in connection with the incident, but he did not reveal the identities of those arrested.
The actual number of casualties was also not disclosed.
“This type of thing should not be allowed, we have already made arrests. Investigations have started and we are asking people who witnessed what happened to come forward and give us statements.
“We are assuring that nobody involved would be allowed to go scot free – this is not the type of case that could be swept under the carpet.
“I learnt that they (NSCDC) officers were pursuing the bus, but I don’t know for what offence but investigations will reveal what happened.
“I want to assure the people that nobody is above the law – whoever breaks the law of the land will face the consequence,” the Enugu police chief told journalists.
But the NSCDC gave a different account of what transpired.
Public Relations Officer of the NSCDC in Enugu, Mr. Denny-Manuel Iwuchukwu, told our correspondent that the commercial transit bus ‘abducted’ a civil defence personnel who entered the vehicle to force the driver to stop for violating traffic regulations.
According to him, the bus fell into the valley, and burst into flames, while running away from NSCDC men, who were chasing the vehicle in a bid to rescue their ‘abducted’ colleague.
Iwuchukwu said the whereabouts of the concerned civil defence officer is currently unknown.
He said, “What happened was that the state government ordered that commercial buses should no longer pick passengers outside the motor park and our men are enforcing the order.
“Today, the driver picked passengers outside the park and he was asked to stop but he refused. So one of our men entered the bus and the driver took off with him, thereby abducting him.
“He was told to stop but he refused, we chased him and he fell inside the ditch – up till now we have not seen our colleague that entered the vehicle.”
Commercial bus drivers and natives of Ngwo town are still protesting around New Market at the time of filing this report.