  The angular distributions of the baryon-antibaryon low-mass enhancements seen
in the charmless three-body baryonic B decays B^+ \to p pbar K^+, B^0 \to p
pbar K_S^0, and B^0 \to p Lambdabar pi^- are reported. Searches for the
pentaquarks Theta^+ and Theta^{++} in the relevant decay modes and possible
glueball states in the p pbar systems are presented. The analysis is based on a
140 fb^{-1} data sample recorded on the Upsilon(4S) resonance with the Belle
detector at the KEKB asymmetric-energy e^+e^- collider.
