A police dispersal order is in place after hundreds of protesters gathered in Portsmouth.
This comes as 140 migrants in one small boat were intercepted in the English Channel.
The vessel left the Jobourg region of Normandy in France earlier.
It was then met in the Channel by two RNLI boats who took the migrants to Portsmouth.
From there, the people were expected to be taken to a processing centre in Manston.
Hundreds of protesters were in Portsmouth on Sunday evening.
Hampshire Police said in a statement on Sunday night that a dispersal order was in place until Monday evening and that officers were "in the area to ensure the prevention of disorder".
A Maritime and Coastguard Agency spokesperson said: "In response to a report on 6 September of a small boat heading towards the Hampshire coast, HM Coastguard sent lifeboats, an HM Coastguard helicopter, an HM Coastguard aeroplane and HM Coastguard Rescue Teams.
"Border Force, Border Security Command, Hampshire Police and South Central Ambulance Service were also sent."
It comes a day after anti-illegal migrant protests blocked the Port of Dover.
Hundreds of masked, black-clad men blocked road access to the Kent port.
Videos showed demonstrators marching through the town and chanting "Stop the boats" as dozens of police officers followed.
Business Secretary Jonathan Reynolds told Sky News's Sunday Morning programme that peaceful protest is not "dressing up in costumes" and "disrupting people's lives".
He declined to comment "on the security and policing side of it" when pressed on the apparent unpreparedness of Kent Police, who described the protest as "spontaneous" in a statement on X.
On the same programme, Reform UK's economic spokesman Robert Jenrick also condemned the disruption, while saying he understood the frustration with small boats crossing the Channel carrying migrants.
(c) Sky News 2026: Police dispersal order in place after hundreds of protesters gather in Portsmouth
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