(AFP) Gunmen suspected to be Boko Haram Islamists stormed the northeast Nigerian town of Gajiran on Thursday, opening fire in a market and killing 15 people, residents said.
Borno state in the northeast, Boko Haram's stronghold where the latest violence occurred, has seen a spate of similar attacks on locals in recent weeks.
Gajiran residents speaking to journalists in the state capital Maiduguri said the gunmen pretended to be traders attending a local market.
"Some of them came aboard trucks while others came on foot to beat the security checks at the entrance of the town," resident Ibrahim Bulama said.
They then "blended among traders conducting business", before opening fire in the market, killing 15 people, he told reporters.
They also set fire to a local government building and a police post, he said.
Another local speaking to journalists in Maiduguri, Aisami Yusuf, also put the death toll at 15 and provided a similar account.
Gajiran is roughly 85 kilometers (50 miles) from the capital.
There has been no mobile phone service in Borno since the middle of May, when Nigeria declared a state of emergency across most of the northeast and launched an offensive aimed at crushing Boko Haram's insurgency.
Details of attacks have been difficult to verify, with area police and military officers unreachable by phone.
The military has said it switched off the phones to block the Islamists from coordinating attacks.
It has also claimed the offensive left the insurgents in disarray and curbed their ability to attack to civilians.
While the violence has persisted amid the military campaign, the pattern of attacks suggests that the insurgents have targeted more remote regions, perhaps where the presence of security forces is reduced.
Last month, insurgents dressed as soldiers opened fire on worshipers leaving a mosque in the far northeastern village of Dumba, killing at least 35 people.
Separately, on August 10 and 11, suspected Boko Haram members stormed a mosque in Konduga and shot dead 44 worshipers as well as 12 other people in a nearby village in another area of the northeast.
Brutal attacks on three schools since July have killed dozens of students.
Boko Haram's insurgency has left more than 3,600 dead since 2009, including killings by the security forces, who have been accused of major abuses.
The group has claimed to be fighting for the creation of an Islamic state in Africa's most populous nation and largest oil producer, though it is believed to have a number of factions with varying aims.
Various attempts to start peace talks with Boko Haram have failed to stem the violence.
Nigeria's 160 million population is roughly divided between a mainly Christian south and mostly Muslim north.
Analysts and diplomats say the insurgency has stalled development and scared off investors, particularly in the north, the most impoverished part of the country.