Nigeria coach Stephen Keshi hit out at American referee Mark Geiger after his side lost 2-0 to France in the World Cup last 16 in Brasilia on Monday.

"The referee is a human being and is bound to make mistakes, but a lot of mistakes is questionable," Keshi told his post-match press conference at the Mane Garrincha National Stadium.

"I'm not happy with the officiating."

Keshi was aggrieved that Emmanuel Emenike had a first-half goal ruled out for offside, although replays suggested the call was correct, and also felt France had been allowed to get away with over-zealous tackling.

Blaise Matuidi was only booked for an ugly challenge on Ogenyi Onazi that ended the Nigerian midfielder's game, while Olivier Giroud escaped punishment after appearing to catch John Mikel Obi with his elbow.

"If you look at the goal we scored, there was no infringement. On two occasions Onazi received very bad tackles and nothing was done about it. He is out now probably for weeks," Keshi added.

"This is the first time I've spoken about the referee in my life, because it wasn't good."

After a hard-fought game in Brasilia, France prevailed through a 79th-minute Paul Pogba header and an injury-time own goal by Joseph Yobo. They will face either Germany or Algeria in the quarter-finals.

Pogba headed the ball into an empty net after Nigeria goalkeeper Vincent Enyeama failed to claim a Mathieu Valbuena corner and Keshi admitted that it had been a costly error by the usually dependable Lille player.

"It's only him that knows the reason he parried the ball rather than punched the ball," Keshi said. "I was a long way away from where has. It was his decision. What happened, happened, and it cost us big."