LAGOS, Nigeria

The Nigerian police have said that 1,844 inmates escaped from jail in an attack on their facility in the southeastern city of Owerri.

Francis Enobore, the spokesman of the Nigerian Correctional Service, said in a statement late Monday the attack took place in the dawn.

Gunmen stormed the prison using explosives to force open the gate, he said.

"The attackers arrived at the center in several Hilux pick-up vans and Sienna buses, armed with sophisticated weapons, and immediately engaged the security personnel on duty in a fierce gun battle. They eventually detonated explosives to gain entry," the official said.

He said six of the inmates have voluntarily returned, while the search for others continues.

An inquiry into the jailbreak has been launched, he added.