An explosion rocked a busy street in downtown Salzburg on Saturday, and authorities said several people were injured. The nature of the blast was not immediately clear. The explosion occurred at about 3:30 p.m. (1330 GMT) on the Bachstrasse, and the Austria Press Agency quoted local Red Cross officials as saying there were multiple injuries. Austrian state broadcaster ORF cited unidentified officials as saying the blast appeared to involve a bottle of liquefied natural gas that exploded at a home. Authorities could not immediately be reached for comment.