There will be another Sonisphere 2014 Knebworth line-up announcement for the rock music festival next week, including a Saturn second stage headliner.

The three-day rock and metal event returns to the grounds of Knebworth House from Friday, July 4 to Sunday, July 6.

Organisers have already confirmed The Prodigy, Iron Maiden and Metallica as Apollo stage headliners.

The 2014 line-up also includes main stage performances from Limp Bizkit, Deftones, Alice in Chains and Frank Turner & The Sleeping Souls.

Promoters confirmed today (Friday) that more bands will be added to the UK leg of the international touring festival on Wednesday, March 5, including one of the Saturn second stage headliners.

The festival’s official Twitter account, @sonisphere, tweeted today: “Just been sent some new bands to put on a poster.”

The festival later added: “Knebworth Band Announcement March 5th 5pm. (That is wednesday folks)”

This news was also spread via social media on the festival’s official Facebook page, with a status update today (Friday) reading: “Band Announcement Wednesday 5th March at 5pm. Spread the word”

Team Sonisphere member and Kili Live booker Alan Day confirmed via his Twitter handle @alandayrocks that a Saturn headliner will be announced.

He tweeted: “announcing more acts for @Sonisphere next week, inc a Saturn headliner that Tommy Vance introduced me to & i’ve been a mega fan ever since.”

The festival’s two main outdoor arenas – Apollo and Saturn – alternate, meaning music fans can see all the acts playing those two stages during the weekend.

Sonisphere 2014 will help celebrate Knebworth’s 40th anniversary of staging outdoor concerts.

As previously announced in the Welwyn Hatfield Times, Sonisphere’s local newspaper, The Prodigy, Iron Maiden and Metallica will headline the fourth UK edition of the international touring festival.

Chart-toppers The Prodigy will play the opening Friday night, with nu-metal favourites Limp Bizkit Rollin’ into Hertfordshire again as their special guests.

British heavy metal legends Iron Maiden will top the Sonisphere bill on the second day.

Bruce Dickinson, Steve Harris, Dave Murray, Adrian Smith, Nicko McBrain and Janick Gers will bring their Maiden England World Tour to a fitting finale at Knebworth, retiring some songs in the process.

American thrash metal giants Metallica will exclusively close the festival on the Sunday night with their interactive ‘By Request’ set list, as chosen by ticket holders.

Also appearing across the weekend are the likes of Slayer, Anthrax, Airbourne, Mastodon, Dropkick Murphys, The Sisters of Mercy, Chas & Dave and Devin Townsend Project.

For further information please visit the Sonisphere Festival website at www.sonisphere.co.uk

* For pictures of previous Sonisphere Festivals at Knebworth, look through our gallery of images.