More than 60 protesters have clashed with police on the driveway of Villawood detention centre as they tried to block the transfer of detainees to Western Australia on Saturday.
Riot squad officers stood guard at the entrance and faced a chanting line of protesters three deep for most of the morning. At one point both sides shoved up against each another in a tussle that threatened to escalate.
"They had me by the neck," a man, who would only give his name as Dan, said. Dan was visibly shaking as he demonstrated how an officer had allegedly pulled his head back.
A man who gave his name as Evan said he had been crushed under protesters and police.
"I fell the first time and tried to get up but they just kept pushing and pushing," he said. "About five people fell on top of me and I heard people yelling and screaming."
Evan said he was stuck until others managed to drag him out from under the crush of people, leaving him with grazes on his wrist and elbow.
Activist Amy Thomas from Glebe spent a sleepless night at the centre's driveway, keeping watch since 12am on Saturday.
"We heard around 10:30 or 11 [pm] that they'd moved the buses inside the detention centre and we suspected they may still move people this morning ... we wanted people out here to watch for that," she said.
"We really didn't want a situation where people could be snuck out in the middle of the night and there's no one here to see them."
Ms Thomas said there was a group of about 40 protesters overnight and that they were reinforced by more who arrived at 6am.
"We may stop the buses for some hours but we're not going to be able to stop it forever," she said. "But we want to send a message to these people that we stand with them."
Officers detained three people at the protest for a "breach of the peace", a police spokesman said, adding that they were not charged and had since been released.
A fourth person, Marlene Carrasco, escaped arrest after an officer accused her of stealing his cap during the clash.
"He told me that I was under arrest for stealing his hat," she said. "Obviously they found it on the ground."
As one young woman handed out bananas from a plastic shopping bag, the crowd around her chanted: "When refugees are under attack, what do we do? Stand up fight back" and "Close the racist prison, deport the politicians".
Jane Healy, from Mothers Supporting Asylum Seekers, said she had come to say goodbye to the asylum seekers inside the centre. Ms Healy said she and other mums from the eastern suburbs and north shore used to go into the centre to meet and talk with the people held inside. "We weren't politicised but we are now," she said.
Ian Rintoul from the Refugee Action Coalition, which organised the protest, believed that the buses held between 36 and 40 refugees.
The government is transferring asylum seekers to a number of detention centres in Western Australia, including the Northam detention centre.
"We're concerned because it's unnecessary," Mr Rintoul said. "And it does impede on legal action most of the people are involved in."
The government has denied any ulterior motive, citing construction work at the Villawood centre.
The black buses left the complex at about 10:30am. Tinted windows meant no one on the street could see inside.