The May rate increase, by 150 basis points, was the bank's first in more than two years.

But in June annual inflation quickened to 18.6%, the highest reading in five and a half years, driven by rising prices of staples like bread, rice and maize and the cost of diesel, which is widely used to generate power.

Emefiele said on Tuesday that all members of the 11-member monetary policy committee (MPC) voted for rates to rise at the latest meeting, although they differed over the size of the increase. Six MPC members, a majority, voted for a 100 basis point increase.

(Reporting by Chijioke Ohuocha and MacDonald DzirutweWriting by Alexander WinningEditing by James Macharia Chege)