On Friday morning the Colombian capital was hit by its fourth low-impact bombing in less than a month, and second in less than a week.
The explosion occurred outside a bank in a Bogotá neighborhood, setting citizens on edge just as the nation's peace process with rebel groups inches its way through what many hope will be its final stages.
No one has died as a result of the spate of bombings, but the incidents have caused damages and injuries, while aggravating a climate of uncertainty for Colombians hoping to achieve peace after fifty years of civil war.
Friday morning's blast was caused by a modified petardo, or firecracker, that went off outside a bank in the Teusaquillo district of the city. Several nearby buildings suffered broken windows from the explosion, which occurred shortly before 5 am.
But no injuries were reported and police at the scene said there were no known motives.
Prior to Friday's explosion, authorities had not offered any possible motives behind the bombings. Each new attempt has been surrounded by confusion and an absence of definitive information. No one has come forward yet claiming responsibility for any of the attacks, and it is not yet clear if the incidents are related.
On Friday, authorities raised the possibility of rebel involvement. National police chief Rodolfo Palomino told Caracol Radio in Bogotá that armed rebel groups may be behind the two recent bombings in the Teusaquillo area — this Friday's explosion, and an explosion that occurred on February 11 at the headquarters of a far-right political party.
"I would not rule out that this was the ELN," Palomino said, before describing the attacks as "actions to generate propaganda and uncertainty."
The National Liberation Army, or ELN, are not participating in the ongoing peace talks in Havana between the Colombian government and the FARC, the country's largest rebel army. The FARC declared a unilateral ceasefire in its conflict with Colombia's government in December.
Although Palomino refused to label the attacks as terrorism, his statements marked the first time that any rebel group has been publicly linked to the recent explosions.
Six bombs in total have been placed on the streets of Bogotá since February 6. Four have been detonated in separate incidents, and two explosives were detonated by authorities in a single controlled incident after the bombs were located and identified.
The string of bombings began with the unsuccessful attempt against a site where a mobile police unit customarily parked, near Bogotá's iconic La Santa Maria bull ring. Two explosive devices were discovered, which authorities said contained shrapnel and other materials and were set to go off remotely using a cellphone.
The placement of the two homemade explosives caused the police to speculate that the attacks may have been targeting security forces, in an area where locals have spent years requesting more protection from criminal gangs.
'Three [bombing attempts] in one week has been seen before in Bogotá.'
The first successful bombing came five days after the first attempt, on February 11, when an explosive device went off at the headquarters of the far-right Citizen Option (OC) party in Bogotá. One person was injured in the blast, which caused damage to 32 buildings.
OC senator Doris Vega took to Twitter to state that the incident had been a "political attack" against the "democracy of this country." Her party then backed the implication, posting a bulletin on its website claiming the attack illustrated the "kind of political violence happening in Bogotá."
The following night, on February 12, an explosion occurred at a small grocery store in the southern part of the city. Bogotá mayor Gustavo Petro alleged that the attacks represent "a systematic plan to alter the order of the city."
"Three [bombing attempts] in one week has been seen before in Bogotá," Petro said.
While violence in the city has dropped significantly — the murder rate in 2012 dropped to its lowest point in 27 years — these attacks remind residents of the nation's long history of internal conflict.
The attacks have also drawn comparison to the wave of car bombings that hit the city in the early 1990s, which the government said had been ordered by the infamous Pablo Escobar, then-head of the Medellin cartel. Those events crippled Bogotá, killing dozens of people, and injuring hundreds more.
Last Monday, March 2, another homemade bomb exploded in a Bogotá, this time at a public parking lot, injuring at least five people, including a six-month old baby, two cyclists, and passengers on a nearby bus. Three buses were also damaged in the blast, which occurred in the Engavitá area of Bogotá.
Authorities speculated that this attack had been an act of criminal coercion directed at the owner of the parking lot. "Explosive at 8:15 pm in a parking lot […] was apparently the result of an extortion," the Engativá mayoral office tweeted on Monday.
However, when VICE News reached out to the police for comment, they would neither confirm nor deny the extortion claim.
"We are looking into the whole issue of cameras, and anything else that's pertinent to this investigation," Gen. Humberto Guatibonza, commander of the Metropolitan Police, said after last Monday's attack.
"It is very dangerous over here," an Engativá resident told a local news outlet. "It is filled with vicious people. People cannot walk alone."
Police at the scene of Friday morning's blast told VICE News that the most recent incident had been caused by a "petardo filled with gunpowder."
Speaking to VICE News, Bogotá police officer Alberto Costilla speculated in an interview that the "improvised, low-impact" devices used in the attacks had been placed by small criminal gangs who intend "to create a culture of panic," and evidently not cause fatalities.
Police are offering a reward of up to 50 million pesos, or about $19,000, for information leading to the identification of those responsible for the bombs. No arrests have been made so far.
Follow Joe Parkin Daniels on Twitter @joeparkdan.