At least two people have been shot dead and 11 wounded after gunmen launched an overnight attack on a church in northern Nigeria, officials say. The attack happened in the Kaduna state town of Zonkwa, which saw serious violence after April\'s election. Kaduna is divided along political, ethnic and religious lines and the BBC\'s Nura Ringim in the state says it is thought to be a revenge attack. Thousands of Muslim Hausas and Fulanis were forced from their homes in April. Our correspondent says that some of those attacked had vowed to take revenge, as had the Boko Haram Islamist militant group, based further north in Borno state. He says some 3,000 people are still living in a camp in the state capital. A police spokesman told our correspondent that some of those shot in the latest attack were in a critical condition.