Civilian militias patrolling the Bulgarian border to intercept and turn away illegal migrants say they are not nationalists, but merely patriots defending their country from Islamist infiltration.

Journalists from NBC News interviewed members of Bulgarian National Movement Shipka – BNO Shipka for short – whom they described as “friendly, courteous and open” despite a fearsome outward appearance.

“I’m not nationalistic or anything like that. I’m just a patriot,” said Nikolai Ivanov, one of the group’s founding members. “Many of these immigrants are not just some guys who are trying to run away from war. They are from age 17 to 35, with good physiques and training.”

Ivanov stressed it was “not a problem that they are Muslims. The problem is it’s a different civilization. They don’t think like us, they have a totally different view about life, about everything.”

Between 50 and 200 migrants a day were crossing the Bulgarian border in 2016, but – like Hungary – the south-east European country has rolled out border fences to reduce the inflow.

Groups of civilians have been patrolling the Turkish frontier for over a year now, but BNO Shipka members have a more militia-like character than the early volunteers.

The group has a YouTube channel with dozens of videos showing members out on patrol and engaging in army-style combatives training. An English-language website lays out its goals more clearly for a foreign audience.

“Our organisations are well supported by Bulgarian Muslims who find in our entities meaningful defence against the crimes of radical Islamists against them and their families and children,” they stress.

“We are on guard at the Bulgarian-Turkish border, the Southern frontier of all Europe, not against genuine refugees but against criminal gangs – radical Islamists, terrorists and ISIS and Al Qaeda fighters – illegally invading our countries with the purpose not of integrating themselves into the societies of the independent European nations, but rather to assault and radicalize forcefully the traditional Muslim communities which have existed and have been functioning with dignity and respect and consider themselves as part of our common life for the last fifty years or more.”

BNO Shipka’s leader, Bulgarian Veterans Military Union chief Vladimir Rusev, paints the migrant crisis as something of an establishment conspiracy, alleging that “ISIS was created not by real Muslim believers but by foreign security services, international financial syndicates and extremists serving vested financial and political interests.”

Rusev calls for officials and politicians “who aid and abet the illegal migration into Europe of nationals of countries outside the EU and so facilitate the occupation and enslavement of their own people” to be prosecuted for treason.

According to NBC, the group claims to have 50,000 members and displays strong Russian sympathies. The ‘Shipka’ in their name refers to the Battle of Shipka Pass in 1887, when a small Russo-Bulgarian force repelled an army of 40,000 Ottoman Turks.

Bulgaria was ruled by the Ottoman Empire for five centuries, a period still remembered as “the Turkish yoke”, and is one of four NATO members where the public say they would choose Russia rather the United States to defend them if attacked.

The other three are Greece, Slovenia and – curiously – Turkey.