The police appealed to residents of the Anambra community to provide them with information.
At least 10 people were killed on Sunday when gunmen attacked Nibo, a community in Awka South Local Government Area of Anambra State, Nigeria's south-east.
The incident occurred during the Nibo Community's celebration of the Onwa Asaa, a traditional festival.
Sources told PREMIUM TIMES that the attackers arrived in a Lexus SUV, entered a restaurant at Oye Nwochichi Market in the community and opened fire on the victims.
"They drove in aggressively and started shooting everyone around, both inside and outside the restaurant," Emeka Ofomata, a witness, told this newspaper.
"We haven't counted the dead bodies. But they (deceased victims) are more than 10," Mr Ofomata said.
A resident of the area, who asked not to be named, said the hoodlums later drove to Eke Nibo Market and shot dead a yet-to-be ascertained number of people.
Viral video
A video clip, apparently recorded after the attack, has been circulating on various WhatsApp groups.
In the clip, many corpses could be seen on the ground in a pool of blood.
One of the victims, whose name could not be ascertained, wore a security shirt which indicated that he may have been a vigilante operative.
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Residents believe those who carried out the attacks were cultists.
Police speak
The police in Anambra State have confirmed the killings.
In a statement on Sunday evening, the police spokesperson in the state, Tochukwu Ikenga, said the incident was "a cult-related clash."
Mr Ikenga, a superintendent of police, did not, however, confirm the number of victims killed in the attack.
The spokesperson said the Commissioner of Police in Anambra State, Nnaghe Obono, has ordered the "immediate deployment" of additional operatives to the area for "necessary action".
He said details on the incident were still sketchy, and that the police were calling on witnesses to assist them with information to aid identification and arrest of the attackers.
Mr Ikenga assured that any information provided would be treated with the "utmost confidentiality."
Worsening insecurity
No group claimed responsibility for the attack.
However, the Indigenous People of Biafra (IPOB) has been linked to some deadly attacks in the South-east.
Security agencies and government facilities are often the targets of such attacks.
But the separatist group has repeatedly denied any involvement in the attacks.
IPOB is leading agitation for an independent state of Biafra which it wants carved out from the south-east and some parts of south-south Nigeria.
