LATE on Saturday morning, on a country road outside the Bulgarian village of Bliznak, ten young men wearing camouflage and combat boots stepped out of their cars, split into groups of three and four, shouted “Long live Bulgaria!” and walked into the woods. The men were volunteers with the Organisation for the Protection of Bulgarian Citizens (OPBC), a year-old civic group based in the coastal city of Burgas that organises tree-planting campaigns and sports leagues—and, since last September, patrols to catch migrants along the Turkish border. It refers to the patrols as “hikes in the woods” to avoid trouble with the police: citizen arrests are illegal under Bulgarian law. “If even one in ten migrants is a terrorist and we catch him, we can save thousands of lives,” says Biser Rusimov. The 30-year-old Mr Rusimov, who works for a company that sells yacht ropes, has the words “Freedom or Death” tattooed on his back, a slogan dating from Bulgaria’s 19th-century struggle for independence from Ottoman rule. He believes he is doing the government a favour: “We want the state to stop the migrants, but since this is not happening, we want to help.”

The state sees things differently. “With their actions, the vigilantes are actually trying to undermine trust in the border police,” says Philip Gounev, Bulgaria’s deputy interior minister.

Since the beginning of the year Bulgarian border forces have apprehended just over 2,800 migrants, 20% fewer than in the same period last year, according to the interior ministry. While over a million asylum-seekers have passed through the western Balkans on their way from Turkey to northern Europe since early 2015, Bulgaria has remained largely on the sidelines. A border fence, construction of which started last year, has helped keep migrants away, but it remains incomplete. With the closure of the main routes through Greece and Macedonia over the past two months, many Bulgarians expect people-smugglers to target their country.

Hence the rise of the vigilantes. Last autumn an OPBC patrol encountered a group of around 30 migrants and handed them over to police. In early April they caught 23 Afghans near the border. Videos of the encounter made by OPBC, and by a local television crew, show members of the group giving the migrants food and water while waiting for police to arrive.

Others have taken the law into their own hands more aggressively. In February Dinko Valev, a 29-year old from the small town of Yambol, was praised in Bulgarian media as a “superhero” for catching a group of Syrian refugees “with his bare hands”. He boasted on national television of patrolling the Turkish border on a quad bike to “hunt” migrants, and has since recruited a group of his own.

Last week another vigilante group from Burgas posted a video on Facebook in which a man ties the hands of three Afghan men behind their backs and forces them to lie on the ground, while shouting “No Bulgaria. Go back to Turkey.” That video prompted outrage both in Bulgaria and abroad; even OPBC condemned the use of force. Petar Nizamov, the man who posted the video, was detained by police and placed under house arrest. The migrants told police they had been threatened with a gun and knives, and searched for money and valuables.

The government has sent mixed signals about this do-it-yourself border policing. After OPBC’s arrest of the Afghans in April, the head of Bulgaria’s border police, Antonio Angelov, travelled to Burgas to present them with an award for their actions. The prime minister, Boyko Borisov, initially said he welcomed the voluntary patrols. But after Mr Nizamov’s video was released, he condemned the practice of citizen arrests and warned that anyone who carried them out would be prosecuted.

Mr Gounev, the deputy interior minister, says the government still encourages citizens to report illegal border crossings and groups of people they suspect are migrants—but that is all. “No further action should be taken by anyone, including detention or citizen arrest, because it’s illegal,” he says.

Human-rights advocates welcome the shift in the government’s position, but say it should have come sooner. Mr Valev was not summoned for questioning over his “bare-handed” apprehension of migrants until a month after his lionisation in the media, following a complaint by the Bulgarian Helsinki Committee, a human-rights group. Margarita Ilieva, who heads the group’s legal programme, says the delay granted the vigilantes legitimacy. “[Mr Valev] doesn’t feel sorry about his actions and he doesn’t plan to stop hunting migrants,” she notes.

OPBC does not plan to give up either. The excursion on Saturday came back empty-handed, though one group claimed to have spotted two migrants who then ran away. OPBC members said they had discovered a few new paths which they believed had been used by refugees, though they might also have been made by locals or even other vigilantes. Either way, they said they planned to come back the next day and continue the hunt.