Bogota: At least five police officers were killed and 41 others wounded when alleged drug traffickers detonated a remote controlled bomb at a station in the northern city of Barranquilla, officials said.

The attack was one of the deadliest on security personnel in recent years, in one of Colombia’s most important cities. It comes as the government of President Juan Manuel Santos seeks to bring the armed conflict that has wracked Colombia for 50 years to an end.

Much of the violence has been financed by drug trafficking. The bombing also casts a pall over preparations for the annual carnival, a major attraction in the Caribbean port city.

Mariano Botero, the Barranquilla police commander, said that the bomb detonated as the officers gathered for morning formation. A police source told AFP that 49 officers were at the site when the bomb exploded.

Of those, five officers aged between 24 and 31 were killed and 41 were wounded. A 31-year-old man was arrested on suspicion of carrying out the attack, according to attorney general Nestor Martinez. “We will charge (him) with five aggravated murders ... attempted murder, terrorism and use of explosives,” he told a press conference.

Barranquilla Mayor Alejandro Char quickly blamed drug traffickers for the attack. “I do not have the slightest doubt that this is a retaliation” for successful police action against drug traffickers, he told reporters.

Botero also suggested that the attack could be in revenge after a police crackdown on local drug traffickers. Colombia is the world’s top producer of cocaine, and criminal groups have flooded the country’s main cities with drugs in a move known as “microtrafficking.”      

El Heraldo, the main Barranquilla newspaper, said some believe the attack may have been aimed at distracting police from an armoured car robbery that took place at the same time. The head of Colombia’s national police, General Jorge Nieto, said he travelled to Barranquilla to offer his support to the blast survivors and their relatives.

He also announced a reward of 50 million pesos (USD 17.8 million) for information about the attack. “We strongly condemn this barbaric act and soon we will find those behind it,” he said.

President Juan Manuel Santos blasted the “cowardly attack” on Twitter. “We will not rest until we find those responsible, my solidarity is with the families of the victims and the wounded,” Santos wrote.