A gunman appears to have been responsible for pumping 17 shots into a Sydney unit block, police say.
The shots were fired at a block of units on The Esplanade in Ashfield at 1.35am today.
Police said one bullet hit the front of a first-floor unit, while a number of others struck an office on the ground floor.
A woman living in the unit was uninjured but shaken by the incident.
Detective Senior Constable John Pollock said police had ruled out a drive-by shooting and suspected it was the work of a single gunman.
"They've apparently come from the same firearm, all of the shots, they appear to be of the same calibre so one shooter is more likely,'' he said.
Police have recovered a number of shell casings, which will be forensically tested.
They remain mystified, however, about the motive for the attack.
"We are still in the process of interviewing the people who are occupying the office and the same for the young lady who was in the apartment," Detective Senior Constable said.
He urged any potential witnesses to the "unusual'' crime to come forward.
"We are looking for witnesses who may have been in the area, seen something, heard something, anything that may be of substance that we can then look at in more detail, [such as] people in the area, people running away, acting suspiciously,'' he said.
Anyone with information can contact Crime Stoppers on 1800 333 000.