One Direction is currently in Amsterdam, as part of the European leg of their sold out "Where We Are" world tour. After getting injured by a thrown object hitting on his knee, Niall Horan urges fans to be cautious of what they carelessly toss on stage at the shows via social media.

In a video clip filmed during the boyband's final performance last night, the 20-year-old pop star was captured struggling to walk a short ramp, carrying his electric guitar strapped across his shoulder. Another footage showed his bandmate Harry Styles being hit in the face with a solid-looking object, while crossing the stage with Louis Tomlinson and Horan.

The Irish singer then took to his Twitter account on Wednesday, June 25 to plead to Directioners in pain. He wrote:

Horan added:

However, Niall Horan did not forget to thank the Dutch city for "a great couple of shows" before the "Midnight Memories" hitmakers move onto an upcoming gig set to take place at San Siro Stadium in Milan, Italy on June 28.

Meanwhile, Horan, who reportedly kissed Irish model Thalia Heffernan when he returned to Ireland last month, apparently tries to keep in touch with the 19-year-old beauty despite their busy schedules.

"Thalia is a really gorgeous girl inside and out. Niall is pretty taken with her. They are still in touch and get on really well," a source told The Sun newspaper. "Niall's never in one place for long and Thalia travels the world modeling, so it will be a case of whenever they can manage it."