Chile condemns 'cowardly bomb attack' in Santiago
Chilean President Michelle Bachelet has condemned a bomb attack on a shopping centre in a busy metro station in the capital Santiago on Monday.
The attack, in which 14 people were injured, is one of the worst since democracy was restored in 1990.
Ms Bachelet called it a "terrorist act, one of the most cowardly we have seen".
There have been around 200 bomb attacks in Santiago in the past decade, with anarchist groups claiming responsibility for many of them.
No-one has so far admitted carrying out this latest bombing.
The president said she would convene a meeting of her security committee on Tuesday to decide how to proceed.
"What's happened is horrible, an abominable act, but Chile is and will continue to be a safe country," Ms Bachelet said.
The explosive device went off at lunchtime at a fast-food restaurant in an underground shopping centre at the Escuela Militar metro station.
About 150,000 people pass through the station daily.
Joanna Magneti, who works in the centre, described the scene: "I was having lunch when I felt the bang. When I went to see what had happened, I saw lots of smoke, people running and shouting, a youngster who was badly injured and a woman with an injured hand."
Three people were badly wounded in the blast, and another 11 are also being treated.
Ms Bachelet said it was "one of the most cowardly acts we've seen because it had as its objective to maim, spread fear and even kill innocent people".
Chile's Interior Minister said Ms Bachelet mother, Angela Jeria, had been in the area at the time the bomb went off.
He said she had been shopping in the centre, but had not been injured. However, he did not indicate whether she may have been the target of the attack.
Police said the explosive device had been planted in a rubbish bin. Metro officials said they would remove bins from key stations as a precautionary measure.
Interior Minister Rodrigo Penailillo said the government "would not rest until those responsible are behind bars".
Bombs regularly explode outside banks and other targets in the capital, such as police stations, army barracks, and the headquarters of political parties.
But the BBC's Gideon Long says most have been timed to go off at night when the streets are largely empty, and only a handful of passers-by have been injured, none seriously.
Our correspondent says that despite years of investigation, police and prosecutors have struggled to bring those behind past bomb attacks to justice.
Ms Bachelet said she would invoke Chile's anti-terror laws which allows for the extended detention of suspects without charge and longer sentences on conviction.
Mr Penailillo said security at metro stations would be increased and called on residents to report anything unusual.