Canberra police have told the ACT Children's Court two people arrested over a series of robberies at the ANU and the University of Canberra appeared to be targeting people of Asian appearance.

Darren Hubert Scott, 19, and a 17-year-old youth were both denied bail on Thursday after they were charged with four aggravated robberies and a theft.

Police told the court they have a strong case, which includes CCTV footage and messages on the teenagers' phones which suggested the crimes were planned.

Police allege one message read, "Do you want to conduct a rob tonight?"

The reply was "Yes I do."

Police also told the court the robberies were opportunistic attacks on people on their own at night, and that students of Asian appearance were targeted.

The items stolen included iPhones, as laptops and wallets.

Youth poses 'significant risk to the community'

Chief Magistrate Lorraine Walker refused bail for the younger teenager in the Children's Court, noting the accused posed a significant risk to the community and there was a risk of interference with the ongoing investigation.

19-year-old Scott appeared in the ACT Magistrate's Court before Magistrate Peter Morrison, who described the crimes as "bizarre "and said he was concerned there was no apparent motive.

Magistrate Morrison said he accepted Scott had not instigated the violence, but noted he was still integral to the crimes.

"The defendant was involved in some level of planning for the subsequent offences," he said.

"It's frankly difficult to accept this as aberrant and a one-off."

Both teenagers are due to return to court later this month.

A 17-year-old woman will also appear.