SANTIAGO, Chile (AP) — Chile sought 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 kept the country on edge Wednesday.

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

While no one has claimed responsibility for Monday's attack in Santiago's posh Las Condes neighborhood, police say they are looking at anarchist groups, which have claimed some of the past attacks.

President Michelle Bachelet boosted security at subway stations and elsewhere and has said she will use the country's tough, dictatorship-era terrorism laws in the case.

Raising tensions were a spate of false bomb scares and two explosions of low-powered homemade devices at supermarkets in 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.

Santiago is one of the safest capitals in Latin America, but residents have been rattled by the series of bombings, especially after Monday's blast was the first to cause injuries. Earlier attacks were small blasts at ATMs, churches and subway stations that caused no casualties. Sometimes the bombs didn't even go off.

"Now I'm thinking twice before I take the subway because I am pregnant," 26-year-old teacher Romina Celle said.

Adding to concerns is Thursday's 41st anniversary of the Chilean military coup that ousted Marxist President Salvador Allende and began the dictatorship of Gen. Augusto Pinochet. Chileans remain divided over Pinochet's 17-year rule and violent protests and clashes with police often coincide with the coup's anniversary.