Adrian Peterson used some harsh words to describe Baltimore Ravens fans on Sunday.

"They've got the worst fans in the NFL," Peterson said following the Minnesota Vikings' heartbreaking 29-26 loss in Baltimore. "(They were) throwing snowballs the entire fourth quarter, like kids.

"It was a bad feeling, a bad feeling."

Peterson, who injured his foot in the loss, also criticized the officiating. Minnesota was whistled for six penalties, including a pass interference call that nullified an interception during Baltimore's game-winning drive in the final minute.

"Some of the calls that were made, you just went, 'Wow. I can't believe that was called,'" Peterson said.

Peterson bemoaned a first-quarter fumble by Minnesota's Toby Gerhart, a play that was upheld by replay review.

"That's just one of them, one out of many (bad calls)," Peterson said. "I wish (the Ravens) the best of luck the rest of the season. The Baltimore Ravens don't make the calls. It's a tough one to swallow."

Gerhart disagreed with the call.

"I felt like I had both knees down, and unfortunately they saw it different," he said. "Immediately, I got up and went to the ref and pleaded my case and told him I was down. It went to review, and they saw it differently."

The two running backs weren't the only Minnesota players upset by some of the calls.

Said fullback Jerome Felton: "There were four plays in there, big calls that went against us that were pretty questionable. So that obviously makes you pretty upset. I'm not happy about that."

Peterson suffered a sprained foot in the second quarter Sunday and missed the entire second half. The league's reigning MVP is set to undergo an MRI on Monday.

Minnesota took a 26-22 lead on Cordarrelle Patterson's 79-yard touchdown reception with 45 seconds remaining.

But the defending Super Bowl champion Ravens answered in stunning fashion with four seconds left, when Joe Flacco found Marlon Brown for the game-winning 9-yard touchdown.

ESPN.com Vikings reporter Ben Goessling contributed to this report.