Gregory Yenlong, the Plateau State information commissioner told The Associated Press that he counted 11 dead bodies at two sites rocked by bomb blasts within the central city of Jos on Friday evening.

An official who spoke on condition of anonymity because of the sensitivity of the issue, said there were also many injured who were being treated at the Jos University Teaching Hospital.

Yenlong said nobody has claimed responsibility for the attacks in a city that has been plagued with religious violence.

Nigeria, a country of 150 million people, is almost evenly split between Muslims in the north and the predominantly Christian south. The attack happened in central Nigeria, in the nation's "middle belt," where dozens of ethnic groups vie for control of fertile lands.

The violence, though fractured across religious lines, often has more to do with local politics, economics and rights to grazing lands. The government of Plateau State, where Jos is the capital, is controlled by Christian politicians who have blocked Muslims from being legally recognized as citizens. That has locked many out of prized government jobs in a region where the tourism industry and tin mining have collapsed in the last decades.

Religious violence has claimed over 500 lives this year in Jos and neighboring towns and villages, but the situation was believed to have calmed down.

"What has happened on the eve of Christmas is unfortunate, especially at this time when we want to ensure peace and security in the state," Yenlong said.

This is the first major attack in Jos since the Plateau State government lifted a curfew on May 20. The curfew had first been imposed in November 2008 during postelection violence but it was extended in January following clashes between Christian and Muslim groups.

More than 300 people_ mostly Muslim — were killed in the January violence in Jos and surrounding villages.

The curfew improved the security within a city that has hosted numerous peace conferences to address the violence but the killings continued outside.

Twelve people were gruesomely murdered in March in a small Christian village, attackers cutting out most of their victims' tongues and there are still regular attacks outside Jos.

The latest killings add to the tally of thousands who already have perished in Africa's most populous country in the last decade over religious and political frictions.