Protests outside the Gabba forced the venue into lockdown while a pitch invader ensured a dramatic opening to the second day of the Brisbane Test.
Groups carrying Palestinian and Aboriginal flags had gathered outside the stadium hosting Australia and West Indies on Friday, with police making at least two arrests in the hours before play was scheduled to begin.
Queuing patrons were stopped from entering, with staff informing them the stadium had been placed in lockdown.
Extra police were stationed outside the Gabba, while the players arrived earlier than normal to avoid the possibility of disruptions.
A Cricket Australia (CA) spokesperson confirmed several protesters had entered the venue, forcing the brief heightening of security.
"There was a small delay as police made sure everything was safe and secure," CA chief executive Nick Hockley told SEN Radio.
A man carrying an Aboriginal flag entered the field of play between the first and second overs, calmly lying down in the outfield as he waited for security to reach him and escort him away.
CA had come under fire from some quarters this week for not using the words 'Australia Day' in marketing around the Gabba Test.
The organisation dropped the term from their marketing in 2021, when some Big Bash League clubs began wearing Indigenous-inspired strips while playing on January 26.
The decision was met with opposition from then prime minister Scott Morrison, who said Cricket Australia should have "a bit more focus on cricket and a little less focus on politics".
But the governing body's position has largely been backed by cricket's playing group, headlined by Test captain Pat Cummins and opener Steve Smith this week calling for the date of national celebration to be changed.
"It's nothing different to everything we've done in the last four or five years," Hockley said.
"We have received some criticism this year, but also received a huge amount of support ... it's a fine balance.
"We just encourage respectful debate.
"(In Cummins we have) a very talented individual but (also) someone who knows himself really well, is very confident in his own skin."
Opener Usman Khawaja has campaigned this summer in support of those affected by the conflict in Palestine, releasing a charity T-shirt and auctioning off boots bearing the slogans 'all lives are equal' and 'freedom is a human right'.
Plans to wear the boots in December's opening Test against Pakistan fell through after his actions were found to flout International Cricket Council rules.
The 37-year-old, announced as the ICC men's Test cricketer of the year on Thursday, promised to continue raising awareness and took to the crease with a bat etched with a dove of peace symbol when he returned to duty in the Big Bash League.