Adams forced to scrap peace concerts
The Canadian rocker was scheduled to sing at a football stadium in Jericho in the West Bank, before heading to Tel Aviv for a second performance.
But both shows were cancelled amid security fears after Palestinian supporters were threatened.
Organiser Daniel Lubetzky said: "Extremist ideologists have threatened our participants in Jericho, and we felt it is our responsibility not to play with their lives. Our mission is not to entertain. It is to mobilise moderate voices. If we have to postpone, we have to postpone."
The events were organised by the One Voice movement, which aims to collect one million Israeli and Palestinian signatures demanding that their leaders reach agreement on a Palestinian state co-existing peacefully with Israel.
Celebrities backing the group are thought to include Brad Pitt, Jennifer Aniston, Rhea Perlman, Danny de Vito and Seinfeld star Jason Alexander.