Shah escaped unhurt when the gunmen began firing at the rally in Khairpur area of Sindh this evening.
The motive behind the attack could not immediately be ascertained.
Several local leaders of the PPP were present at the rally.
Witnesses and official told TV news channels that a journalist was among the injured.
Shah is a member of the National Assembly or lower house of parliament and a former mayor of Khairpur district.
She is a campaigner for the rights of women and a member of several parliamentary committees.
