At least 12 people have been shot dead in Nigeria's northern Adamawa state, police say, the latest in a number of attacks thought to be linked to the armed Islamist group, Boko Haram.
At around noon on Friday, armed men opened fire at a town hall in Mubi, a town near Nigeria's border with Cameroon.
Okey Raymond, 48, who was at the town hall at the time of the attack, told the Associated Press news agency: "We started hearing many gunshots through the windows. Everyone scampered for safety, but the gunmen chanted: 'God is great God is great' while shooting at us."
Raymond said he hid under a table and escaped out a back door.
Ade Shinaba, the Adamawa police commissioner, said Friday's attack targeted a hall where a group of Nigeria's Igbo people of the southeast were meeting. Shinaba blamed Boko Haram for the killings.
A purported spokesman for Boko Haram claimed responsibility for the attack on Friday, the AFP news agency reported, as well as for a separate attack on a church in the northern state of Gombe on Thursday.
"We are responsible for the attacks in Mubi and Gombe," the spokesman who goes by the name Abul Qaqa, told journalists in the northeastern city of Maiduguri by phone, as reported by AFP.
The group previously threatened, through the same spokesman, to begin specifically targeting Christians living in the country's Muslim north in its increasingly bloody fight with Nigeria's weak central government.
Boko Haram, whose name loosely translates to "Western education is sacrilege", is believed to favour implementation of Islamic law across Nigeria, a multi-ethnic nation of more than 160 million people.
Residents of Mubi told Al Jazeera's Ahmed Idris that the attacks on Friday occurred at a meeting to discuss the deaths of four others from the Igbo community who were killed in the town the day before.
"The first attack took place last night when four people were killed, and as people gathered this morning to discuss the matter and deliberate, gunmen suddenly appeared on the scene and started shooting and another 10 to 12 people were killed there," our correspondent said from the capital Abuja on Friday.
The attacks in Adamawa followed the killing of six people who were shot at a church in Gombe on Thursday.
Ahmed Muhammad, the state police spokesman, confirmed in Gombe city on Friday that six people were killed and eight others wounded in the shootings at the Deeper Life Christian Ministry Church.
John Jauro, the church pastor, said confusion broke out when the assailants opened fire and that his wife was among the dead.
"I was leading the congregation in prayers," he said.
"Our eyes were closed when some gunmen stormed the church and opened fire on the congregation. Six people were killed in the attack."
The number of attackers was not clear. Police said an investigation was ongoing.
State of emergency
The Boko Haram spokesman on Friday told journalists: "We are extending our frontiers to other places to show that the
declaration of a state of emergency by the Nigerian government will not deter us.... We can really go to wherever we want to go.
"The attacks are part of our response to the ultimatum we gave to southerners to leave the north," AFP reported Qaqa as saying.
On Sunday, the spokesman had issued a three-day ultimatum for Christians living in Nigeria's mainly Muslim north to leave the region or they would be killed.
The ultimatum came after a day after President Goodluck Jonathan declared a state of emergency in parts of four states hit hard by violence blamed on Boko Haram, particulary Christmas bombings that killed at least 40 people.
Nigeria's weak central government has been slow to respond to Boko Haram. On December 31, Jonathan declared regions of Borno, Niger, Plateau and Yobe states to be under a state of emergency - meaning authorities can make arrests without proof and conduct searches without warrants.
He also ordered international borders near Borno and Yobe state to be closed.
However, the areas where the recent church and town hall attacks happened are not in the areas marked by Jonathan.
Boko Haram is accused by the government of killing at least 510 people last year alone, according to an AP count.