Gardai are investigating a shooting near Merrion Square, and are trying to track down a taxi driver.
Armed units were dispatched to the Boyne Street flats during lunchtime on Monday, after Gardai received reports of gunfire.
Witnesses described seeing a young man sprinting away from the complex, while a gang chased him, firing shots as he fled.
All of those involved had left the scene by the time Gardai arrived, but a woman in her 20's was arrested during a follow up operation.
She has since been released without charge.
Gardai are now making a special appeal to the driver of a silver Kia taxi, who picked a woman up from the Pearse Street area at around 1pm on Monday, bringing her to St. Vincent’s Hospital.
The Garda Confidential Line can be contacted on 1800 666 111.
