Niall Horan has begged fans to be careful with what they throw at him.

The One Direction star and his bandmates performed in Amsterdam on Wednesday night and apparently things got a bit out of hand while they were on stage.

“Can you limit what gets thrown on stage please! Coz somethin thrown at me tonight! Hit my knee! A lot of pain from it!” the 20-year-old tweeted.

“Never wana sound like I'm complaining! But only having my operation 5 months ago, I still get a bit of pain and I'm very scared about it (sic).”

One Direction took a brief break at the start of the year allowing time for Niall to recover from the knee surgery, before kicking off their Where We Are Tour in April in Bogota, Colombia.

Niall was reportedly seen limping in pain off the Amsterdam stage. Bandmate Harry Styles was also struck by a wayward object during the performance. Still, Niall wasn’t overly upset with the fans that came out to the show.

“Amsterdam thank you for a great couple of shows! Appreciate you coming (sic),” he tweeted.

Fans responded to the singer’s plea by tweeting “#FeelBetterNiall”.

Earlier this week One Direction performers Harry and Liam Payne stopped by the set of Sesame Street to sing with Bert.

Midway through the a cappella, Bert stopped to ask Liam, “I thought you forgot the lyrics.”

“I was just waiting for you to finish,” Liam replied. “I thought you were going to do some big crescendo.”