Amy Winehouse arrived in Belgrade to launch a comeback tour this weekend, and proceeded to slur and sway through an anemic performance one Serbian publication called "the worst" concert that locals have ever seen. Tickets were considered exorbitant in a region where citizens earn some of the lowest wages in Europe.

A backup singer took over lead vocals on songs she was struggling with, and boos from the Belgrade audience were widely reported. At one point, the BBC says Winehouse threw her mic to the floor, when she wasn't mumbling lyrics. On video, seen after the jump, she's seen resting on equipment and wandering the large stage.

The troubled singer, 27, was in and out of rehab recently, in advance of her tour. But now, her rep says Monday's gig in Istanbul and Wednesday's concert in Athens have been scrapped because "she cannot perform to the best of her ability" and feels "this is the right thing to do." Her tour will resume July 8 in Spain.