A cell of suspected Islamist militants has opened fire on security forces in Nigeria's capital Abuja, say officials.
The clash occurred at about 03:00 local time after a tip-off about the location of a suspected Boko Haram weapons cache, Nigeria's spy agency said.
The State Security Service did not give any details about casualties. A witness told the BBC he saw nine bodies.
However, other witnesses told Reuters news agency the shooting came during an attempt to move squatters.
Six witnesses told Reuters the house was owned by a military man who wanted them to leave his property.