The incident happened in Well Hall Road just before 8.40pm on April 24.
Officers were called to the scene and found that the group was known to each other.
A man was arrested on suspicion of two counts of common assault.
The 46-year-old has now been released with no further action.
Safeguarding measures have been put in place for the group involved.
A spokesperson for Metropolitan Police said: “Police were called at 8.40pm on Monday, 24 April to reports of a fight taking place at Well Hall Road, SE9.