Mutya Keisha Siobhan tease 'Flatline' video 

in behind-the-scenes snaps

The girls are in Los Angeles to shoot the video with director KT Auleta.

They shared pictures on their social networks, offering a first look behind-the-scenes at what fans can expect.

http://instagram.com/mutyakeishasiobhan

Earlier this week the girls spent time with Adam Lambert, who later tweeted:"I love u all! Such down to earth, smart, real ladies!! What a pleasure!"

Mutya Keisha Siobhan play their first headline show in over 12 years at London's Scala on August 1st. Tickets for the gig sold out in 14 minutes when they went on sale last week.

'Flatline' is available to pre-order on iTunes, ahead of release on September 1st.