In a resealable plastic bag, combine the mustard and Worcestershire sauce. Add water, soy sauce and oil; remove 1/3 cup and set aside for basting. Cut chicken into 1 1/2 inch pieces; add to bag. Seal and refrigerate for 1 1/2 to 2 hours. Drain, discarding marinade. Thread chicken and vegetables alternately on skewers. Baste with reserved marinade. Grill over hot coals for 10 minutes. Turn and baste. Cook 10 minutes more or until chicken juices run clear.