U2 announce North American tour support

U2 have announced more groups who will support them on their North American tour.

Kanye West, Arcade Fire, Damian Marley and Patti Smith have now joined the ranks of those to warm up the American crowds for the Irish rockers.

Keane and Dashboard Confessional were previously confirmed as touring with the band.

The 'Vertigo' tour began September 12 in Toronto with Dashboard Confessional opening for the first eight dates, to be followed by Keane from October 3 in Boston.