The concert held Tuesday at the Canyon Club was the Foo Fighters' first full-capacity show since the start of the pandemic.
The anti-vaccine demonstrators protested the requirement that attendees show proof of a COVID-19 vaccination. Among those protesting included former child star Ricky Schroder.
Schroder was critical of frontman Dave Grohl and referred to the musician on social media as an "ignorant punk" for supporting a vaccination requirement.
The Foo Fighters say the band plans to keep the rule for its show at Madison Square Garden this weekend.