Scottish singer KT Tunstall was caught up in a stand-off between riot police and protesters in London on Tuesday (11Jun13) as officers cracked down on demonstrators ahead of the upcoming G8 conference.

The star was horrified as officers in riot gear stormed the streets around the radio station where she was recording an interview, and she snapped a picture of a police line outside the building.

She posted the image on her Twitter.com page with the caption, "Actually behind the riot police line at Absolute Radio... Full on."

Tunstall later added another picture which showed police officers holding back protesters.

Demonstrations kicked off in the U.K. capital on Tuesday ahead of this month's (Jun13) gathering of world leaders at the G8 Summit in Northern Ireland, and hundreds of police took to the streets to keep the peace.