By Darren Franich
Updated June 19, 2011 at 12:00 PM EDT

Amy Winehouse has canceled two tour dates in the wake of an ill-fated concert in Belgrade, according to CNN. During the performance, the singer staggered through several of her songs until loud boos from the audience finally forced her from the stage. (Video taken at the performance shows a disoriented Winehouse mumbling occasional lyrics and walking aimlessly around the stage.) Following the performance, the singer canceled planned concerts in Istanbul and Athens. Winehouse recently left a British rehab facility; this twelve-city tour, her first in years, was intended as a comeback for the troubled singer.

More on Amy Winehouse from EW:

Amy Winehouse falls apart on stage in Belgrade: Video