Chile asks for international help in subway bomb case, while scares, blasts keep tensions high

A police officer directs the curious away from a blast site at a subway station in Santiago, Chile, Monday Sept. 8, 2014. A bomb exploded in the Chilean subway station injuring at least seven people, the most damaging in a string of bombs planted around the country's capital this year. (AP Photo/ Luis Hidalgo) (The Associated Press)

Police explosives experts, walk out of a subway station after a false alarm bomb alert in Santiago, Chile, Wednesday Sept. 10, 2014. President Michelle Bachelet boosted security at subway stations and elsewhere and has said she will use the country's tough, dictatorship-era terrorism laws, after Santiago was rattled by a series of low powered bombings. (AP Photo/ Luis Hidalgo) (The Associated Press)

A police explosives expert enters a subway station during a false alarm bomb threat, in Santiago, Chile, Wednesday Sept. 10, 2014. President Michelle Bachelet boosted security at subway stations and elsewhere and has said she will use the country's tough, dictatorship-era terrorism laws, after Santiago was rattled by a series of bombings. (AP Photo/ Luis Hidalgo) (The Associated Press)

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.