Video footage appeared to show police restraining several protesters on George Street, with some people pinned to the ground.

Speakers on the steps of Flinders Street Station addressed a crowd of up to 200 people, with the protest briefly blocking traffic.

‘We need to be part of that in Australia’

Across Europe, thousands of protesters took to the streets in Dublin, Paris, Berlin and Geneva to condemn Israel’s interception of the flotilla. Rallies also took place in Buenos Aires, Mexico City and Karachi.

“[The Australian government] needs to sanction the Israeli government and stop the diplomatic support,” one organiser of the Melbourne rally, Alec, told SBS News. “To fight for the right of the activists to not be locked up against international law.”

“Protests are breaking out now all around the world … and we need to be part of that in Australia too,” they said in an Instagram reel.

Activist says they haven’t heard from Australian on board

“That was the last I heard of him. So that was roughly 14 to 16 hours ago now.”

Israeli officials have warned: “If it approaches, its attempt to enter an active combat zone and breach the blockade will also be prevented.”

DFAT liaising with Israeli authorities

“We understand that people want to help deliver aid to those suffering in Gaza — we also want to see critical aid delivered.”