Four NSW teenagers have been charged after a spate of alleged robberies and assaults that left five men hospitalised.
Detectives made the arrests after investigating a series of incidents on the state's north coast between late-October and mid-November.
The separate incidents at Evans Head and Ballina saw five men - aged 77, 58, 53, 50 and 27 - hospitalised after being seriously assaulted.
Police allege the men in each incident had agreed to meet a person they had been talking to online.
They would arrive at an agreed location before being assaulted and robbed by the teens.
Following inquiries, detectives seized a white ute from a Broadwater property on Thursday before it was forensically examined.
Police then arrested a 16-year-old during a vehicle stop in Broadwater and laid multiple charges against him, including wound with intent to cause grievous bodily harm.
On Friday police arrested and charged a 17-year-old after he attended Ballina Police Station; he faces charges including aggravated robbery and wound with intent to cause grievous bodily harm.
The 16-year-old and 17-year-old were refused bail to face children's court on Friday.
Later on Friday police arrested two more 17-year-olds in Broadwater, charging them with aggravated robbery with wounding and intent to cause grievous bodily harm.
Both were refused bail and were due to face children's court on Saturday.
Police searched homes across the north coast and Northern Rivers regions, and seized drugs and goods suspected of being stolen during the assaults.
Investigations continue and police urged anyone with information to come forward.