BEIJING — Local officials in eastern China are investigating complaints that more than 100 children received expired polio vaccines after aggrieved parents protested violently over the weekend, the latest in a string of such vaccine scandals that have provoked anger nationwide.

The government of Jinhu County in Jiangsu Province said on Friday that 145 children had received oral polio vaccines after their December expiration date. The children were between the ages of 3 months and 4 years, according to the state news media.

In a statement on its website, the Jinhu government said that the incident exposed “the negligence and supervision failure of the relevant departments.”

The county discipline commission is investigating senior local officials, including the deputy county head, according to the statement.