A man wearing a backpack and acting erratically has been arrested inside Melbourne's Crown Casino, sparking the evacuation of hundreds of staff and customers.
The bomb squad and critical incident response team were called to the Southbank complex on Wednesday afternoon over concerns about the 55-year-old.
"It was the way he was acting and behaving," Acting Commander David Clayton told reporters near the scene after the man was arrested without incident.
"We understand he may have made some statements and we're just confirming those.
"There has been nothing found in the backpack as yet."
He declined to say whether the incident was terror-related.
Hundreds of staff and customers were evacuated from parts of the casino, while the bomb squad swept the complex before it was deemed safe.
Crown was due to re-open on Wednesday evening.
A chef at Cafe Baci, inside the Crown complex, said staff earlier received a series of text messages telling them to avoid "level one and western side of the complex".
"Everyone was in the dark about what was going on. No one really said anything," he told AAP.
"Police came and said 'we're closing down the place. You guys can stay inside'."
"A lot of the restaurants, they took a lot of the staff and the patrons out over the bridge."
Images posted on social media showed cars blocked off from the Crown car park and people on the street near police cordons.
In a statement, Crown said: "an isolated incident occurred at Crown Melbourne involving one patron."
"The issue was resolved peacefully with the assistance of Victorian Police."
