Explosion at Colombia shopping mall leaves 3 dead, 9 injured The mayor of Bogota called the incident a "cowardly terrorist attack."

 -- An explosion at a Colombia shopping mall left three people dead and nine injured on Saturday, ABC News has confirmed.

Enrique Penalosa, the mayor of Bogota, Colombia, called the incident, which took place in the women's bathroom on the second floor of Centro Andino, a “cowardly terrorist attack.” Police said the explosion was caused by a device placed behind a toilet bowl.

One of the deceased has been identified as Julie Huynh, a 23-year-old French national who had spent the past six months volunteering in the public school sector. The other two died were also women, ages 27 and 31.

Of the injured, one is in grave condition but is expected to survive, while the other eight are in less serious condition.

It's unclear who's responsible. An anti-terror investigation is being conducted by the Colombian prosecutor’s office.

The U.S. Embassy in Bogota offered condolences in a series of tweets, adding that it's standing by to "provide any support requested by the Colombian authorities."

Centro Andino is home to a number of high-end stores including Dolce & Gabbana, Versace and Louis Vuitton.

ABC News' Joshua Hoyos contributed to this report.