A number of people are expected to be charged after Sydney police attempting to disrupt what they say were planned illegal climate change protests were allegedly set upon.
Officers were carrying out investigations around a property at Colo Valley on Sunday when their vehicle was surrounded by a group who shoved them and let down tyres, Detective Superintendent Paul Dunstan says.
The police, attached to Strike Force Guard, were approached by a number of people who set about circling them as they moved towards the vehicle, he said.
"They pushed, shoved, jostled the police before they managed to enter the vehicle, at which point a group of people commenced damaging the vehicle, letting down the tyres and preventing the vehicle from leaving the area," Superintendent Dunstan said.
"The police fortunately managed to leave the area after a struggle and some time ensued."
Superintendent Dunstan said he believed "the group was engaging in behaviour, planning and preparing to conduct the extreme forms of protest that this group has conducted previously".
He added: "Practising, rehearsing and constructing items to conduct similar methods of protest they conducted during March protest activity, where you saw at Port Botany, elaborate objects being formed and used and put in the middle of the roadways to ultimately disrupt vehicle activity in trains in and around the city area.
"This is not traditional protest activity. This is criminal activity. There are a number of ways to conduct lawful protests.
"In fact, we conduct hundreds, if not thousands of protests in and around the Sydney CBD each year."
Police said earlier the officers had been assisted by specialist units including PolAir, the dog unit, riot squad and police rescue.
The operation was carried out at a camp occupied by members of climate activist group Blockade Australia.
Zelda Grimshaw, a climate activist connected with Blockade Australia, told AAP the group was nonviolent.
"I don't believe that anyone would have committed an act of violence," Ms Grimshaw, not present at the site, said.
"I heard that a couple of groups of heavily-armed men in camo gear were found in hills around the property. So that was very alarming," she said.
"One of the groups has been asked to leave by people camped at the property so that may well translate into whatever it is that the police are describing."
Ms Grimshaw said about 100 police officers had descended on the property.
She said five people had been arrested and everyone on the property had been detained.
The group included a 19-year-old and a 92-year-old retired teacher, Ms Grimshaw said.
Officers were in the area after receiving information a group of about 30 to 40 were gathering to prepare for upcoming protests, Superintendent Dunstan said.
Police intended to carry out investigations at the property but the activity brought their plans forward.
Superintendent Dunstan said police remained at Colo Valley and had executed a search warrant, with further arrests and charges expected after two people were earlier taken into custody.
