Twelve people were injured on Wednesday after a bomb exploded in front of a Colombian intelligence agency in the city of Pasto, near the Ecuadorian border.

[Carlos Prieto, Injured Victim]:          
"I didn't see anything. People were just running, but I don't know anything."

Police and rescue workers rushed to the scene.   

[Hernando Palacios, Red Cross Worker]:
“These people have been sent to the emergency room. This report is from the hospitals of the city where the patients have been taken."

The medium sized explosion at the Administrative Department of Security, or DAS, building is the latest in a series of attacks over the past week against government institutions. 

Sources say three people were being held in connection with the bombing.  

Pasto is the capital of Narino province. It's also the key to the drug production and smuggling operations of the Revolutionary Armed Forces of Colombia (FARC) and the National Liberation Army (ELN). 
           
The once powerful and influential FARC and the ELN have stepped up activities since the instatement of President Juan Manuel Santos last month.