Just Stop Oil climate protesters fired an orange flare next to the 17th green at the 151st Open Championship at Royal Liverpool in Hoyllick on Friday before being removed from the course by police in a golf cart.
Orange powder was seen near the edge of the green a short distance from the playing surface but second inning play continued without delay.
A statement from tournament organizers said the R&A read: “A protester was quickly arrested on the 17th hole and is one of four people arrested by the police. Play was not disrupted and we would like to thank the marshals, players and other spectators for their vigilance and understanding while removing the protestors.”
The Open has become the latest UK sporting event to be targeted by a group of climate activists this summer. Just Stop Oil protesters also disrupted Wimbledon this month and the third Ashes test of cricket at Lord’s.
The World Snooker Championship and the Gallagher Rugby Championship final were both targeted earlier this summer.
Merseyside Police confirmed four arrests on suspicion of conspiracy to commit criminal damage and public nuisance.
“Merseyside Police respect the right to protest and express opinions but anti-social, criminal or disorderly conduct will not be tolerated and will be dealt with firmly,” the police said in a statement.
“The Police Department and the Research and Development Department will look to ensure that the activities of anyone who wants to protest do not disrupt the event itself and, if necessary, we will use relevant legislation to deal with the people involved in it.”
“Contingency plans are in place for visitors to enjoy these events in safety and with minimal disruption.”