rtokens: He said police backed by explosive experts were combing the area in search of other possible weapons or explosive devices .
pos: " PRP MD VB JJ NN RB JJ IN CD NNS ( NNS ) RB IN WRB PRP VBD VBD , " DT NN VBD .
tokens: " They could cause serious damage as much as 500 meters ( yards ) away from wherever they were detonated , " the spokesman added .
ltokens: " These are powerful weapons , " a spokesman with the Municipal Police told Reuters by telephone , adding that police had not ruled out a possible terrorist attack on the ornate Casa de Narino presidential palace in Bogota 's historic downtown area .