Nigeria's top military officer on Wednesday dismissed talk of a possible coup in Africa's most populous nation, which is currently in the grip of a raging Islamist insurgency and unrest.

"Why should anyone be thinking in negative fashion? Tell them we will not do it. Those rumouring coups must be living elsewhere and not in Nigeria," said Chief of Defence Staff Alex Badeh.

The Boko Haram uprising, which has killed thousands across Nigeria's north since 2009, combined with ethnic and sectarian strife as well as a weakened government, has led some commentators to openly suggest that the situation could lead to a military takeover.

Nigeria gained independence from Britain in 1960 but six years later experienced its first coup, and in 1967 a brutal civil war broke out over the secessionist aims of the Biafra people in the country's east.

There was a brief period of civilian rule between 1979 and 1983 before a succession of coups in the mid-1980s to late 1990s. Nigeria returned to democracy in 1999.

Air Chief Marshal Badeh dismissed talk of a military takeover in a statement issued by Nigeria's National Orientation Agency, which promotes government programmes across the country.

"The armed forces are defenders of democracy. We are an arm of democracy. So how can an arm of democracy work against the democracy that we are part of?" he asked at an event in Abuja.

Badeh expressed surprise at the coup rumours but called the military a professional group that "has no option but to love Nigeria".

Nigeria's military recently embarked on seizures and searches of national newspapers on what it said were security grounds, prompting some media to claim that the government was trying to stifle free speech.

One daily likened the action to the dark days of censorship under military rule.