A top Nigerian police official and three others have died in a helicopter crash in the country's central region, officials have said.

Haruna John, the deputy inspector general of police who led national operations, died in Wednesday's crash in Jos, police spokesman Yemi Ajayi said.

Nigeria's police website said John had been carrying out a routine patrol over Jos with two other officers and a police pilot who also died.

Jos had long been a religious flashpoint city before finding relative calm for much of the last year.

The suicide bombing of a Catholic church last week has threatened to re-ignite religious violence in the area.

At least 10 people died in that blast and in retaliatory violence, with reports suggesting a series of drive by shootings, including attacks on policemen in Nigeria's second largest city of Kano.

Source: Al Jazeera and agencies