Charges over violent Sydney robberies

A 14-year-old boy has been charged following three violent but unrelated street robberies on Sydney's eastern beaches.

In the first incident on April 13, a 23-year-old man was robbed at knife point by a man on Beauchamp Road in Matraville about 11.30pm.

The armed man allegedly fled the scene with his credit cards, mobile phone, wallet and cash.

Police have charged a 48-year-old woman over the incident and she will face court next month for receiving stolen property and dishonestly obtaining financial advantage.

In a separate robbery five days later, a 29-year-old woman was walking along Anzac Parade in Maroubra when she was struck to the head from behind and knocked to the ground.

Two thieves snatched her backpack, which was allegedly discovered by officers a day later inside a unit on Anzac Parade. The woman's bank cards had also been used.

A 24-year-old woman has been charged with dishonestly obtaining property and receiving stolen property over the incident.

Meanwhile, a 14-year-old boy has been charged with assault with intent to rob and three counts of robbery in company after officers seized mobile phones and clothing from a unit on Kennedy Street in Kingsford on April 18.

He was refused bail to appear at a Children's Court next month.

Detective Acting Superintendent Leanne McCusker says the robberies are unrelated, despite occurring within a few days of each.

"We believe each person was randomly targeted for these street robberies, and since these swift arrests no further offences have been committed," she said.