We search for massive resonances decaying into a quark and a vector boson, qW or qZ, or a pair of vector bosons, WW, WZ or ZZ, where each vector boson decays hadronically. We focus on resonances which are sufficiently heavy to result in energetic vector bosons; the decay products of each vector boson are then merged into a single jet, and the event effectively has a dijet topology. The analysis relies on recently developed techniques in the area of jet substructure and uses them to suppress QCD dijet background. The data sample corresponds to an integrated luminosity of 5.0~fb−1 of proton-proton collisions collected in the CMS experiment at the LHC. We set a 95\% C.L. lower limit on the mass of excited quark resonances decaying into qW (qZ) at 2.32 TeV (2.04 TeV).