A vehicle airbag includes at least one chamber configured to be inflated when the airbag is triggered and at least one gas generator fluidically connected to the at least one chamber for filling the at least one chamber with a gas. At least one respective interior tensioning bag is arranged in the at least one chamber at each opposing chamber end. The two tensioning bags are configured in such a way that during the filling of the at least one chamber, they synchronously tension and deploy the chamber.