Arctic Monkeys will headline this year's Open'er festival in Poland, it's been announced.

The Sheffield band join previously announced headliners Kings of Leon at the event, which will take place from the July 2nd-5th.

Placebo, Moby, Duffy and Basement Jaxx will also perform at the festival.

Open'er will also feature performances from The Kooks, The Ting Tings, Madness and Crystal Castles.

In total, over 120 acts will perform at the event, which this year will take place over four days for the first time.

Last year the Open'er was headlined by the likes of Bjork, Chemical Brothers, Muse and The Beastie Boys.

(by Jason Gregory)