On Tuesday, the State Department, through its embassy in Bogota, called on US citizens in several Colombian areas, including the troubled Putumayo region which has been a haven for coca production and leftist rebels, to boost their security precautions in response.
"The embassy has received information of an increased terrorist threat against US citizens in the departments of Putumayo, Huila, Cauca and Narino," it said in a notice to Americans issued on Monday.
"US citizens in these departments in particular are urged to review their security posture and practices at this time," the embassy said in the notice.
The warning, which also noted that "the threat of terrorist acts against US citizens remains a high concern" throughout the country, is the fourth for Colombia issued by Washington this month.
On 11 December, the embassy in Bogota warned of a "high
probability of terrorist" attacks in the capital and alerted US
citizens to similar "credible" threats in the resort city of Cartagena.
Nine days later, the State Department renewed a broader warning for Americans to avoid travel to Colombia, noting an increased threat to US citizens and interests from "narco-terrorist groups and other criminal elements."
On 23 December, the embassy in Bogota repeated concerns about the potential threat to US interests in Cartagena and said that its employees in the city had been advised "to maintain a low profile and avoid frequenting public places, such as restaurants and shopping malls."
However, that same alert also rescinded a month-old ban on US embassy employees visiting two neighbourhoods in northern Bogota - Zona Rosa and Parque 93 - where grenades were tossed into bars on 15 November, killing one person and wounding 72 people, including three American citizens.
US embassy in Bogota warns
of possible "terrorist" attacks
Colombian authorities blamed the leftist Revolutionary Armed Forces of Colombia (FARC) for the attack, although the rebel group denied responsibility.
The FARC, along with the left-wing National Liberation Army
(ELN) and the right-wing paramilitary United Self Defence Forces of Colombia (AUC), have all been designated "foreign terrorist organisations" by the United States.