Witnesses who declined to give their names out of fear the sect would target them said the gunmen stormed into the service and began firing. Most escaped, though as people came out of hiding later they found the pastor dead in a pool of blood in the sanctuary, witnesses said. Four other worshippers died in the attack, they said.

Borno state police spokesman Samuel Tizhe later confirmed the attack took place and said officers would investigate.

Representatives of Boko Haram, who typically speak to journalists at times of their choosing in telephone conference calls, could not immediately be reached for comment Sunday.

Boko Haram is waging a growing sectarian battle with Nigeria’s weak central government, using suicide car bombs and assault rifles in attacks across the country’s predominantly Muslim north and around its capital, Abuja. Those killed have included Christians, Muslims and government officials. The sect has been blamed for killing more than 450 people this year alone, according to an Associated Press count.

Diplomats and military officials say Boko Haram has links with two other al-Qaida-aligned terrorist groups in Africa. Members of the sect also reportedly have been spotted in northern Mali, an area where Tuareg rebels and hardline Islamists seized control over the past month.

In January, a coordinated assault on government buildings and other sites in Kano by Boko Haram killed at least 185 people. In the time since, the sect has been blamed for attacking police stations and carrying out smaller assaults in the city.