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 of Maiduguri.
Hamidu Ahmad, a resident, said the gunmen went into town "chanting `Allahu Akbar` and burnt down the divisional police station and three churches".
"I saw two bodies in police uniform not far from the police station. One of them was sprawled by the roadside while the other was seated in a police van," resident Sani Kani said.
Another local witness gave the same report but said it was not immediately clear whether worshippers were in the churches at the time of the attacks.
Residents reported gun battles between the assailants and police reinforcements who arrived from Maiduguri.
Police and the army could not immediately be reached for comment.
Boko Haram has often targeted churches in its bloody insurgency, as well as police and other symbols of the establishment in Nigeria.
On November 25, 11 people were killed in twin suicide bombings targeting a church at a military barracks in the northern town of Jaji.
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.
Two weeks ago leaflets were circulated around Gamboru Ngala by suspected Islamists saying that women were required to wear the Muslim veil and banning the sale of cigarettes, residents said.
"A tailor named Adamu was shot dead last week by some suspected Boko Haram members for making clothes for women the group consider obscene," said resident Hajara Umar.
Boko Haram, which can be loosely translated from the northern Hausa language as "Western education is a sin", has claimed many attacks in northern and central parts of Nigeria, Africa`s most populous country and top oil producer.
Nigeria`s population of some 160 million is roughly divided between the mainly Muslim north and the predominantly Christian south. (M014)
Editor: Kunto Wibisono
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