Colombian officials are reporting no injuries or damage from three small explosions as Western Hemisphere leaders arrived for a summit.
Two of the low-intensity blasts occurred in Cartagena where the summit is being held and one was close to the U.S. Embassy in Bogota.
The explosions occurred as more than 30 presidents and prime ministers arrived for the sixth Summit of the Americans.
A senior military official says two bags of gunpowder exploded in a vacant lot about a quarter mile (400 meters) from Cartagena's bus station Friday evening. The official spoke only on condition he not be further identified.
Bogota security officials say the third explosive device was set off near a tree in a drainage ditch near the U.S. Embassy, which is heavily fortified.