A Muslim congregation in central Georgia that wants to build a mosque faces opposition from an armed “3%” militia that has terrorized county officials and smeared the mosque as a training ground for the Islamic State.

The militia’s actions have forced the cancellation of a county meeting meant to discuss the application to build the mosque, a move commissioners blamed on “uncivil threats or intentions [that] must be taken seriously”.

Questioned by the Guardian, the county sheriff said investigations into the activities of the militia, which released a video in which the site of the proposed mosque appeared to be trespassed upon, had involved “limited conversations”.

Another officer asked the Guardian to forward any information it had on the militia’s leader.

The imam of the congregation issued a statement in which he called for all concerned to follow the example of the prophets, who he said “exercised patience and treated their neighbors well”.

“This all started back in August,” Macrae Brennan-Fuller, spokeswoman for Newton County, told the Guardian with a sigh.

The members of Al Maad Al Islami have worshipped for a decade at the home of imam Mohammad Islam in tiny Doraville, Georgia, but the congregation has now become big enough to need its own building.

The members bought 135 acres about 40 miles south of Atlanta, in rural Newton County. The mosque would only require a small section of the land, which would otherwise be used for a cemetery, a park and possibly a school.

Newton County is solid Trump country, however, and the presidential candidate’s suspicion of Muslim immigrants revealed itself in local reaction. On 11 August, county commissioner John Douglas asked in the Rockdale Citizen newspaper: “Would building those things make us a prime area for the federal government to resettle refugees from the Middle East?”

Soon there was a Facebook page, called Stop the Mosque, alongside videos of armed and masked men firing weapons and setting off explosives in Georgia’s woodlands. The hashtags, the camouflage getup and clumsy maneuvers might have seemed silly, except the ammunition and demolition equipment were real.

By mid-August, Newton County’s commissioners had enacted a temporary ban on building any places of worship, a reversal for a body that a few years ago passed a zoning ordinance designed to allow unimpeded construction of places described as “cathedral, chapel, church, synagogue, temple, mosque, tabernacle”.

An opposing outcry arose in support of the mosque, and the US Department of Justice reviewed a complaint by the Council on American-Islamic Relations. Under pressure, the commission set a date in mid-September to lift the ban. But just before meeting day, a militia emerged, calling itself the Georgia Security Force III% (GSF).

Three Percenters are a collection so-called patriot groups, scattered around the US and loosely affiliated. They draw their name from a claim that only a noble 3% of the American colonies’ population fought against the British in the American revolution. In reality, the colonies’ population at the time was about 2.5 million, of whom half were women, others were children, others old or infirm – and about 250,000 still fought.

The Georgia group’s leader, Chris Hill, is a paralegal who also goes by the pseudonyms Bloodagent Hill and Chris Doberman. He did not return messages from the Guardian. But according to the group’s site and social media, its members hold a range of contradictory views.

They are training to fight both the US government and enemies of the US government; they wave both the American flag and the southern Confederate battle flag; they say they support the US constitution but not the right of Muslims to express religious freedom.

As the Newton County meeting approached, the GSF released a video set outside a church across the road from the mosque’s proposed site. In it the force’s members – some paunchy and gray, some teenage and waifish – stood in poses, holding up three-fingers like a misplaced street gang. But their guns were real and their rhetoric was incendiary.

The video has since been taken down but Hill, a former US marine, claimed the proposed mosque had ties to Isis training, the September 11 attacks, the Boston marathon bombing, the Fort Hood shooting and more. Its members, he said, followed the antichrist. Another man hung an American flag on what appeared to be the mosque’s future site, an act which would have required trespassing.

The posts shook the Newton County commission. It canceled the meeting and posted a notice on its website: “A self-made video circulated on social media of a militia group from a neighboring county, may have been trespassing on private property, and exhibiting harassing or violent behavior.

“Unfortunately in today’s society, uncivil threats or intentions must be taken seriously.”

Brennan-Fuller, the county’s spokeswoman, said the commission never met to lift the temporary ban, which expired on 20 September.

“I hope that’s the end of it,” she said.

That seems unlikely. After the GSF bullied the Newton County commission, Sheriff Ezell Brown pledged to investigate the group. Reached on Wednesday by the Guardian, he said: “I’ve had limited conversations about it.”

Brown’s spokeswoman, Sergeant Courtney Morrison, said: “We don’t have any reports against the security force.”

Hill, the GSF leader, lives in neighboring Henry County. Captain Joey Smith of the Henry County police said he had heard of the protests but did not know Hill lived in Henry County. He said someone in the department may know of Hill, and asked the Guardian to forward its information on him.

“Anything you have would be helpful,” he said.

The congregation, in the meantime, hopes to make peace with its new neighbors before breaking new ground.

“As Muslims, we believe that God has commanded us to follow the teachings of the prophets Adam, Noah, Abraham, Moses, Jesus and Muhammad, who exercised patience and treated their neighbors well, even in the face of injustice,” Imam Islam said in a written statement.

“For that reason, we consider building bridges with our neighbors far more important than immediately building a new cemetery and house of worship.”