Five suspected far-right activists from Britain were detained in northern France last Thursday, according to authorities.
The "anti-migrant" group had been travelling on a minibus which they nicknamed "the battle bus" and were in possession of four tear gas bombs, said officials in the Hauts-de-France region.
The five, who were apprehended in Grande-Synthe, about four miles from Dunkirk, had been broadcasting live on social media, "images intended to illustrate acts of intimidation" against migrants trying to reach the UK, it was alleged.
Authorities said the suspects were placed in police custody and have been accused of participating in a "group formed with a view to preparing violence against persons and for transporting category D weapons without legitimate reason".
The Dunkirk prosecutor's office is involved in the investigation and the five are expected to be "expelled" from France.
Officials in the Hauts-de-France region said 10 other suspected far-right activists from Britain, who were detained under similar circumstances earlier this year, have been slapped with bans from French territory.
"The state does not tolerate such actions conducive to hatred and violence from anyone," said the X account of the Prefecture de la region Hauts-de-France et du Nord.
It is the official government administrative body which represents the state in the Hauts-de-France region and the Nord department.
On Saturday, the UK government announced almost 1,000 migrants crossed the English Channel in small boats to the UK in two days, as better weather led to calmer conditions.
Officials said 263 people in three boats made the journey on Thursday, which ended a three-week pause in crossings from France.
That was the longest spell without arrivals this year amid high sea swell and wind in the Channel.
Then on Friday, 671 people in nine boats made the journey to Britain.
More from Sky News:
The King to speak about slavery with 'unflinching honesty'
Flights disrupted after 'illegal' drone activity near airport
With crossings usually lower during late autumn and winter, data suggests the total number of crossings this year is unlikely to surpass the figure for 2025.
According to the Home Office, the total number of arrivals for 2026 was 21,869 after Friday's crossings. The figure for the whole of 2025 was 41,472.
Crossings are down significantly, with the lowest number of summer arrivals since 2020 recorded this year, the government said.
In April, Home Secretary Shabana Mahmood signed a three-year £662m deal which was expected to see French police removing hundreds of migrants from beaches every year.
Riot police would be sent to stop migrants entering the Channel as part of measures which came into force in the summer, typically the busiest time for crossings.
(c) Sky News 2026: Suspected far-right activists from Britain 'with tear gas bombs' detained in France, say aut
Five teenage boys seriously injured after being stabbed at party on Halloween
The King to speak about slavery with 'unflinching honesty'
University of Cambridge scientist died in Spain train crash
Flights disrupted after 'illegal and persistent' drone activity near airport
Virgin Media O2 to axe thousands of jobs in sweeping shake-up
'Significant development' in Leeds murder investigation as man arrested in London
National Grid sparks deal to pave way for giant UK data centre
Police arrest 325 people during Palestine Action protest
Man charged with explosives offences in Belfast
