Two campaign staffers working for a right-wing candidate in Colombia's upcoming presidential election have been shot and killed, officials said Saturday.

Gunmen on motorcycles killed the two men Friday night in the central-west Meta Department, said the candidate, Abelardo de la Espriella.

Meta is a stronghold of rebel fighters who rejected a historic 2016 peace accord with the now-defunct and once-powerful FARC guerrilla army, and also a conduit for cocaine trafficking.

The government's citizens' rights ombudsman said on X that as the killings come in the lead-up to elections, they "seriously affect" people's ability to take part.

Security is a big issue heading into the May 31 election to replace Colombia's first leftist president, Gustavo Petro.

Colombia is enduring a wave of killings and rebel attacks, and de la Espriella and two other major candidates — including leftist front-runner Ivan Cepeda — have reported receiving death threats. All three travel with heavy security.

Cepeda's vice presidential running mate was kidnapped for a few hours in February by rebels who refuse to embrace the 2016 accord with FARC.

Another renegade group is suspected of killing presidential hopeful Miguel Uribe in June of last year.