BEIJING -- The Chinese government said Saturday that it has fired six more officials in connection with a scandal over faulty vaccines that has undermined President Xi Jinping and fueled parent-led protests.

The government removed six senior officials from the China Food and Drug Administration for their role in a scandal that left hundreds of thousands of children with faulty vaccines for diphtheria, tetanus and whooping cough. Another four officials accused of wrongdoing were fired Thursday after a meeting of Xi and other Chinese leaders.

The dismissals marked the latest attempt to quell public anger over the incident, which has hurt confidence in the nation's health care system and raised questions about Xi's leadership. Criticism of officials and companies has swelled since news of the defective vaccines emerged on social media in July, and parents have organized protests to demand compensation for the affected families.

While the government has said the children were unharmed, the case has touched a nerve among Chinese parents frustrated by years of similar food and medicine scandals.

In an attempt to ease the anger, Xi and other top officials vowed severe punishments for those involved in the misconduct. They said Thursday that 35 officials would be held accountable.

"Vaccines are a matter of public health and national security," the Politburo Standing Committee, which Xi leads, said in a statement that was published by Xinhua, the official news agency. "This case resulted in a negative impact and exposed many loopholes."

The committee also urged the China Food and Drug Administration and local government agencies to engage in "profound self-criticism."

Xi's personal oversight of the punishments reflected his determination to move beyond the scandal at a difficult moment in his presidency.

Xi's critics have grown louder as he has faced a series of troubles, including a heated trade dispute with the United States and a slowing economy. His vast centralization of power has left him especially vulnerable to criticism in moments of crisis, experts say.

"There's no one else to blame when scandals like this erupt," said Jude Blanchette, a political analyst who is a senior adviser at Crumpton Group, an advisory and business-development company.

The government focused its investigation on a drug producer in northeast China, Changchun Changsheng, which was accused of making 252,600 doses of ineffective vaccines. The company's chairwoman and 17 other employees were detained last month in the case, according to state news reports.

Last week, the government said it had discovered that Changchun Changsheng, in Jilin province, had produced a second batch of 247,200 faulty vaccines, for a total of 499,800 doses. Officials say the company falsified data and used expired ingredients. Most of the vaccines were given to children in eastern China.

"In its reckless pursuit of profits, the company committed grave unlawful acts," Xinhua said in a report Thursday.

The six officials at the China Food and Drug Administration who were dismissed Saturday were blamed for failing to catch safety violations at Changchun Changsheng.

The four officials fired Thursday were Bi Jingquan, a former head of the China Food and Drug Administration; Jin Yuhui, a vice governor of Jilin province who oversaw food and drug safety; Li Jinxiu, another Jilin official who supervised food and drug safety; and Liu Changlong, the mayor of Changchun, the provincial capital.

A former top official at the China Food and Drug Administration, Wu Zhen, is subject to a corruption investigation, Xinhua said.

Parents said they were still angry about the vaccines and were skeptical of the government's vow to clean up the industry.

"We don't really care who has been punished," said Min Wen, a father from the southern city of Guangzhou who has pushed the government to compensate the families of children who received the bad vaccines. "We care about who will be responsible for our children."