Suspected members of the Islamist extremist group Boko Haram set fire to churches and border posts in north-eastern Nigeria on Sunday, residents said, but it was not immediately known if there were casualties.
Around 50 gunmen in cars and on motorcycles carried out the attacks on three churches and border posts with neighbouring Cameroon, opening fire on police and chanting Allahu Akbar, (God is Greatest), residents said.
Among the security posts burned were offices for immigration, customs and the secret police and a quarantine building in the city of Gamboru Ngala, about 140 kilometres (80 miles) from the Boko Haram stronghold in Maiduguri.
"The gunmen believed to be Boko Haram were around 50 in number and came in cars and on motorcycles around 8:30 am and attacked the security offices at the border posts, burning them," resident Modugana Ibrahim told AFP.
"They opened fire on the security personnel but it is hard to say if anybody was hurt or killed," Ibrahim said.
Another resident, Hamidu Ahmad, said the gunmen went into town "chanting 'Allahu Akbar' and burnt down the divisional police station and three churches".
Violence linked to the Boko Haram insurgency in northern and central Nigeria is believed to have left some 3,000 people dead since 2009, including killings by the security forces.