The ticked-off Alive singer halted the group's gig in Milton Keynes to rant, telling fans, "There are people out there who are looking for a reason to kill!"
He added, "They're looking for a reason to go across borders and take over land that doesn't belong to them. They should get the f**k out and mind their own f**king business."
As fans cheered his anti-war stance, Vedder added, "What the f**k...? They're f**king dropping bombs on each other. What the f**king f**k?"
The group then performed a cover of Edwin Starr's peace anthem War, before Vedder returned to his rant, stating, "Everyone's the f**king same, so why are people at war? Stop the f**king s**t, now! Now! Now! We don't want to give them our money. We don't want to give them our taxes to drop bombs on children!"
Vedder was not specific about who he was targeting, but he has been attacked by Israeli groups, who feel sure his frustrations were aimed at them amid their ongoing conflict with Palestinian leaders.