A “co-ordinated” protest in the UK that appears to be “illegal migration-related” has seen hundreds of black-clad, masked demonstrators block roads in Dover, a local councillor said.

Videos online show dozens of men, dressed in black and wearing balaclavas, gathered at the port.

Dover is the UK’s busiest international ferry and passenger port, dealing with 9,128,648 passengers by road last year and 2,119,030 freight vehicles, according to the port’s website.

Councillor Chris Vinson, leader of the Conservative group and the member for Walmer on Dover District Council said the protest appears to be “illegal migration-related”, but said that the demonstrators do not appear to have placards or banners.

He said: “Overnight, clearly what appears to be several hundred masked men wearing black clothing and balaclavas seem to have co-ordinated and loaded into rental vans and then descended on roads leading in and out of Dover with the intent to block them, and that’s what they’ve successfully done, and it’s brought the town to a standstill.

“There are stacks of people who are stuck in their cars or in their workplaces as a result.”

He added: “I’m not aware that there’s been any violence, although clearly, having the path of your vehicle blocked by men wearing black paramilitary gear and balaclavas is extremely intimidating, especially when it’s not clear why they’re there, and the police weren’t aware and so haven’t been able to warn people in advance and make sure that they are made to feel safe.”

He said he knows people who worked night shifts in the port who are “being prevented from leaving for fears for their safety”.

He added that there were women in cars “feeling intimidated, people stuck in traffic – who obviously are without toilet facilities – queues way back on the A20 and the other approach roads into Dover”.

The UK government has condemned the actions.

A Government spokesperson said: “The right to peaceful protest is fundamental to our democracy, but we condemn the behaviour in Dover and the travel disruption it has caused.

“We appreciate the frustration of those who have been impacted today.

“Access to the port is now restored and traffic is flowing. Those travelling to the port are advised to allow for extra travel time and to follow guidance from providers.

“We thank policing partners and travel providers who we continue to work with to ensure the safety of passengers and the wider community.”

The Port of Dover said in a statement on X earlier that the disruption is affecting “all routes” in and out, as well as around the town.

It said: “The Port of Dover can confirm that there is an ongoing public order incident happening around the town of Dover.

“This is affecting all routes in and out the port and the town. We are in contact with Kent Police to understand the situation.

“This situation is impacting our local community and our customers, so of course we are hoping for a swift resolution.”

Videos of the scene show dozens of protesters milling around roads and roundabouts near the major port, forcing vehicles to a halt.

Others show demonstrators linking arms in a blockade across the A20, shouting “stop the boats”. Activists could be seen marching along the A-road, chanting: “England ’til I die.”

In a post on social media, the activist Tommy Robinson suggested today’s protests in Dover were part of a co-ordinated plan.

He wrote on X: “Simultaneously at different locations across Dover patriots have mobilised to close down the port.

“There are three plus locations that patriots have shut down so far with many more planned to be closed.”

In a statement on X, Kent Police said: “We are aware of a protest currently taking place at the Port of Dover. Officers are in attendance and engaging with protesters.”

Shipping company DFDS said: “We are aware of the current traffic disruption affecting access to the port.

“Rest assured we will accommodate you onto the next departure once you arrive.”

P&O Ferries said its sailings are “still going ahead as scheduled”, adding that those who miss their departure will be offered the next available crossing.

National Highways said the protests had caused 6km of traffic congestion on local roads, causing delays of up to 45 minutes.

Labour MP for Dover and Deal Mike Tapp criticised the masked men and said he was in contact with the police.

“I am fed up with idiots coming to Dover to cause disruption. I bet if you asked any one of those ‘protesters’ they wouldn’t know small boat crossing are down by 40% and we are working hard to fix the mess. Go home, enjoy your weekend/get a job,” he said on Facebook.

Reform UK councillor for Dover West Paul King said he was told the demonstration is a “stop the boats protest”.

“We don’t condone causing public disturbance by protest. But it’s a very good example of what is happening daily with the boats coming in,” he said.