Updated

Chile is seeking help from foreign security agencies in identifying those responsible for an explosion that injured 14 people at a subway station in the capital, while bomb scares and small blasts are keeping the country on edge.

Prosecutor Raul Guzman hasn't said which countries have been contacted, but says "international agencies" have been asked for help in the investigation into the blast. It was the latest in a wave of 29 small bombings or attempted bombings in Santiago this year.

Raising tensions were a spate of false bomb scares and two explosions of low-powered homemade devices Wednesday at supermarkets in the city of Vina del Mar. One woman reported damage to her ears from one of the blasts, which appeared designed to make noise but cause little damage.