A social leader is killed nearly every other day in Colombia. Notably, nearly all of the victims have been very local leaders or activists, with no national profile. This has spread terror among social leaders, sending the message that you’re not safe no matter how unknown you are.

While the most prominent national human rights and social leaders get constant death threats, they’ve seen few actual attacks lately. That’s why the May 4 attack on the Black Communities’ Process (PCN) leadership in northern Cauca is an alarming milestone.

Those who narrowly escaped a 15-minute barrage of rifle fire and grenades were top national leaders of the country’s Afro-Colombian movement, gathered for a strategy meeting. People widely known in Colombia like Francia Marquez, winner of the 2018 Goldman Environmental Prize, Carlos Rosero, Víctor Moreno, and Clemencia Carabalí.

They were part of a group of 25 people, including children and international accompanies, gathered in a meeting space in the rural zone of Santander de Quilichao municipality, about an hour south of Cali. At 5:30 on Saturday—broad daylight—four unknown men showed up. Carlos Rosero told El Espectador that the leaders were in the rear of their building when they heard “a shootout,” and all threw themselves to the floor. Three of the unknown men began firing and throwing at least one grenade. Two of the leaders’ government-provided bodyguards were wounded.

Afterward, two assailants left by motorcycle, and two on foot, on the only road leading back to Santander de Quilichao’s town center. A PCN communiqué notes that there are three police or military road checkpoints nearby, one about 10 kilometers (6-miles) away.

President Iván Duque called the attack a “terrorist act” in a tweet, and promised to activate his government’s “Opportune Action Plan” for protecting social leaders. Still, the attack heightens a growing sense that Colombia’s post-peace accord security gains are eroding.

Assassinations of nationally prominent social leaders were brutally frequent in the 1990s and early 2000s, the darkest period of Colombia’s conflict. Government-aligned, landowner and drug trafficker-supported paramilitary groups and hitmen took the lives of human rights lawyers like Hector Abad Gómez, Jesús Maria Valle, and Josué Giraldo; researchers like Mario Calderón and Elsa Alvarado; academics like Jesús Bejarano and Alfredo Correa de Andreis; and satirists like Jaime Garzón, among dozens of others. But this hasn’t happened to nationally prominent activists in a while.

The May 4 attack may be a sign of trouble to come. The ELN, guerrilla dissidents, neo-paramilitary groups, and organized crime structures are all growing, as documented in a report issued last week by the Bogotá-based Ideas for Peace Foundation. And according to 57 observers around the country interviewed by Colombia’s La Silla Vacía investigative journalism site, “there are more allegations of abuses by the security forces, including extrajudicial executions,” since Iván Duque took office last August.

How can Colombia stop the deterioration? The recommendation is not a new one: find out who ordered, planned, and paid for attacks like Saturday’s vicious assault in Cauca, and bring them swiftly to justice while respecting due process. As long as there’s little probability of that happening, brazen acts like this one may proliferate—and Colombians’ repeated claims that “this is a much different country than it was 20 years ago” will ring hollow.