LIMA, Dec. 24 (Xinhua) -- A bomb exploded on Monday in the Bolivian Workers' Federation (COB) building in La Paz, Bolivia's administrative capital, shattering windows but harming no one, according to reports reaching here on Monday.

    The explosion took place in the entryway to the building, police said. It was very close to where COB executive secretary Pedro Montes sleeps, but he was away from La Paz at the time.

    COB secretary Sosimo Paniagual described the event as "unheard of" and blamed far-right groups opposed to the incumbent government. He added that the COB would continue to back the government in its bid to radically reshape the nation.

    The Fire Brigade and the police told media that they would investigate.