Police in Chile say a small bomb exploded and broke some windows at a U.S. cultural institute hours ahead of President Barack Obama's arrival.
No one was injured in the attack, which happened in Vina del Mar, a seaside city far from the Obamas' activities in the capital of Santiago.
Police captain Nibaldo Lillo said the bomb caused only minor damage. Nobody immediately claimed responsibility for the attack at the Chilean-North American Institute, where people can read books in English and receive language lessons.
The Obama family's visit comes under tight security, with sharpshooters and more than 2,000 police deployed in the capital.