LAGOS, Dec. 28 (Xinhua) -- Nigerian police said it is curtailing a violence that broke out on Monday in some part of northern Nigeria's Bauchi State.

"We are curtailing its spread," Emmanuel Ojokwu, the country's police spokesman, told Xinhua on phone.

He said the state command has ordered its armed policemen to curtail it spread.

"For now, we are studying the situation before making any further comment," he added.

Sources in Bauchi said they woke up into the pandemonium, as sporadic gunshots were heard across the city.

The cause of the crisis could not be ascertained as at the time of filling this report.

In July, the state witnessed a sectarian unrest that erupted in northern Nigeria's Bauchi State that spread to neighboring Adamawa, Kano, Bornoand Yobe States where about 600 people were reportedly killed.

Nigeria is a secular country with the population evenly divided between Christians and Muslims.

The northern region with 19 out of the country' s 36 states is predominantly Muslim, while Christians dominate the south.