MAIDUGURI, Nigeria - Overnight attacks by Boko Haram Islamists forced authorities on Monday to impose a 24-hour curfew in Maiduguri, northeast Nigeria, closing the airport and shutting roads into and out of the city.
The government in Borno state said the decision was taken after consultation with the military, which is believed to have been the target of the strikes by hundreds of militant fighters.
"The imposition of the curfew is necessitated by an attack in Maiduguri by people suspected to be Boko Haram members in the early hours of today," said state government secretary Baba Ahmed Jidda.
The apparently large-scale attack in a major urban centre will cast further doubt on military claims that Boko Haram, which was last month designated a terrorist group by the United States, has been pushed into remote areas.
At the weekend, the military said they would tighten security in communities near Nigeria's northern and eastern borders with Chad, Niger and Cameroon due to fears about Boko Haram strikes over the Christmas and New Year period.
Army spokesman Ibrahim Attahiru told AFP on Monday that one of the attacks struck near the city's airport but he was not able to provide further details, amid reports that the airport and a nearby air force base were targeted.
The phone network has been down in Borno since mid-May, when the government imposed a state of emergency in the state and two others in a move designed to block militants from co-ordinating attacks.
Details of the ongoing conflict have been difficult to verify because of the communications black-out.
The latest violence began at around 3:00 am (0200 GMT) and included bomb and gun attacks, said an AFP correspondent in the city, where Boko Haram was founded more than 10 years ago.
"They entered Maiduguri from the bush, chanting 'Allahu Akbar' (God is great)," said one Nigerian intelligence officer, adding that some insurgents had been detained, without specifying numbers.