Two men from London aged 25 and 27, a 45-year-old woman from London and a 26-year-old woman from Epsom, Surrey, were arrested on suspicion of conspiracy to commit public nuisance.
A spokesman for Devon and Cornwall Police said: “The items and the vehicles have been seized by police as part of ongoing inquiries in relation to this matter.
“We continue to support the facilitation of safe and legal protest but criminal activity and public disorder will not be tolerated.”
Unsurprisingly, the battle against coronavirus will take centre stage this year.
In a statement ahead of the event, the British government said: “The UK is taking on the Presidency of the G7 at a critical time for the world, and as we prepare to host the COP26 UN Climate Conference in November.
“With new vaccines offering a way to end the pandemic, we will use our G7 Presidency to fight and build back better from coronavirus.”
More to follow