Gunmen unleashed fresh terror in Imo State on Thursday, killing several passengers.
Although the police confirmed the Abor Umulolo in Okigwe Local Government Area attack, they gave no figure on the casualties.
Amnesty International quoted 30, sparking apprehension across the state.
The police blamed the attack on the Indigenous People of Biafra (IPOB), saying one of the gunmen was killed in a shootout with security agents.
A manhunt has been launched for the rest of the gunmen, according to the police.
The police said the gunmen suspected to be members of IPOB/ESN launched the attack on commuters in Onuimo and parts of Okigwe in the early hours Thursday, killing several people and burning vehicles.
Security agents who were deployed in response to the attacks came under fire from the gunmen.
The police said the hoodlums were overwhelmed by the superior fire power of the security agents.
One of the assailants was consequently gunned down in the encounter while others fled with varying degrees of bullet wounds.
The police said the gunmen, operating in three groups, barricaded the highway at about 0400 and shot sporadically before setting vehicles ablaze.“A full-scale search and cordon operation is currently underway, with security operatives combing nearby forests and surrounding areas where the suspects are believed to be hiding,” the police said.
Corolla with registration number ENU 283 CN and an HP laptop were recovered from the scene.
Police spokesman in the state, Henry Okoye said the body of the neutralised suspect was deposited at the morgue, while the recovered items are in police custody for further investigation.
He said an intensive manhunt has been launched to apprehend the fleeing suspects and bring them to justice.
The Command urged residents to remain vigilant and report any suspicious persons or activities to the nearest police station.

Madukwe B. Nwabuisi is an accomplished journalist renown for his fearless reporting style and extensive expertise in the field. He is an investigative journalist, who has established himself as a kamikaze reporter.