At least seven people have been reported killed in Nigeria's capital, Abuja, in what security services said was a shoot-out between security forces and members of the Boko Haram Islamist militant group.
The security services said Boko Haram militants had opened fire on a security team searching for an arms cache in a building.
Authorities said several people were wounded, but did not mention any deaths.
Witnesses, however, gave a different account of what happened.
Several witnesses said security forces raided a building owned by a military man but occupied by squatters.
They said the troops opened fire on the squatters killing at least seven.
Boko Haram is active mainly in the north of Nigeria, where it wants to establish Shari'a law.
Its last known attack in the capital occurred in November.
Based on reporting by Reuters and dpa