Last year, the ELN also carried out a bomb attack in the urban center of Bogota, wherein over 40 police officers were injured.
The developments threw into peril efforts to definitively end Colombia's half century of conflict that recently had looked close to resolution.
Mayor Alejandro Char says one suspect has been arrested and two more identified.
"This cowardice and treacherous attack will not go unpunished", Colombian President Juan Manuel Santos told the country.
At least five police officers were killed and 41 others wounded Saturday when alleged drug traffickers detonated a bomb at a station in the northern city of Barranquilla, hours after a auto explosion ripped through a security post near the border in neighboring Ecuador.
"My patience and that of the Colombian people have their limits", Santos said.
Santos' defense minister, Luis Carlos Villegas, put the blame for all three "of these awful acts of terrorism" on the ELN.
A blast from an improvised explosive device hit a police station in Barranquilla, Colombia's largest port city on the Caribbean coast, injuring dozens of people.
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Four minutes were added on as stoppage time in total in the first half. "We had to show character in the second-half". Salah pulled a goal back in the 78th minute with a well-hit shot into the bottom corner.
A 31-year-old suspect in the Saturday blast was taken into custody, with Villegas saying: "This person has a very clear record with the ELN".
Police were the targets of two more bombings late Saturday and early Sunday.
The two attacks didn't appear to be related, but they underscore the security challenges that have emerged since a 2016 peace deal with the Revolutionary Armed Forces of Colombia, which long played a dominant role in South America's drug trade.
His government opened the talks with the ELN a year ago in Ecuador after reaching the peace agreement with the FARC, which has now disarmed and transformed itself into a political party.
In a statement on its main website on Monday, the ELN said it would support a new ceasefire but that attacks would continue in the absence of one.
The rebels had indicated a willingness to resume negotiations.
Peace talks between the Colombian government and the ELN destabilized following attacks that took place over the weekend.
"All our solidarity is for the relatives of the slain police", he wrote on Twitter.