A policeman stands at the site where an explosion occurred at the office of the Porvenir pension fund in downtown Bogota Thomson Reuters BOGOTA (Reuters) - Two small bombs exploded in Bogota, Colombia's capital, on Thursday afternoon, injuring seven, according to the defense minister, who said he would deploy greater numbers of military and police onto the streets in response to the "terrorist doings."

Defense Minister Luis Carlos Villegas did not blame any group for the explosions, neither of which caused serious injuries. They come at a time of renewed security concerns in Colombia after several high-profile attacks on infrastructure by FARC rebels.

President Juan Manuel Santos departed early from a regional summit in neighboring Peru to chair a security meeting after the explosions, both of which targeted the offices of a private pension fund, Porvenir, in the financial district.

Though there was no confirmation of who was responsible, speculation quickly turned to the leftist Revolutionary Armed Forces of Colombia, or FARC, after its recent attacks on major oil pipelines that cross the mountainous country.

The FARC has repeatedly bombed oil pipelines in the last few weeks, causing thousands of gallons of crude to spill into major rivers, killing fish and leaving thousands to fetch drinking water from tanker trucks.

The FARC has been in peace talks with the government, hosted by Cuba, for two and a half years. But it stepped up bombings of oil pipelines when the government resumed aerial bombings of the group's jungle bases after the rebels ambushed and killed 11 soldiers.

A FARC commander, Matias Aldecoa, in Cuba to participate in the peace negotiations, said in a press interview this week that the group planned to switch from attacking infrastructure to targeting members of the police and armed forces. In a video message on Thursday, he said his comments were misinterpreted.

(Editing by Leslie Adler)