A 56-year-old woman has been charged following the alleged assault of a four-week-old baby in Braddon.

About 4.30 on Saturday afternoon, a mother was walking with her four-week-old child in a pram along Ijong Street when they were approached by another woman.

Police allege the woman blocked the path, reached into the pram, grabbed the baby and flung him to the ground.

The mother took the baby to hospital for medical treatment and the matter was reported to police.

On Wednesday, a 56-year-old woman was taken into custody and charged with one count of recklessly inflicting grievous bodily harm.

Police are also investigating a second incident near Ijong Street, where a woman was allegedly assaulted immediately before this incident.

Witnesses to either incident are urged to contact police via the ACT Crime Stoppers website or by calling 1800 333000.