Iran’s morality police have resumed patrolling the streets to force women to wear the Islamic headscarf after pulling back in response to nationwide protests over the death of a 22-year-old woman in their custody. 

Authorities had struggled to contain the mass protests sparked by the death of Mahsa Amini in September. The protests largely died down earlier this year following a brutal crackdown in which over 500 protesters were killed and nearly 20,000 detained. 

Though morality police were rarely seen patrolling the streets, authorities insisted throughout the crisis that the rules had not changed. Iran's clerical rulers view the hijab as a key pillar of the Islamic revolution that brought them to power more than four decades ago.

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A police spokesman said Sunday the morality police would resume notifying and then detaining women not wearing a hijab in public. In Tehran, the men and women of the morality police could be seen patrolling the streets in marked vans. 

The battle over the hijab became a powerful rallying cry last fall, with women playing a leading role in the protests. The demonstrations quickly escalated into calls for the overthrow of Iran's clerical rulers, whom the mostly young protesters accuse of being corrupt, repressive and out of touch. Iran's government blamed the protests on a foreign conspiracy, without providing evidence.

Several Iranian celebrities joined the protests, including prominent directors and actors from the country's celebrated film industry. Several Iranian actresses were detained after appearing in public without the hijab or expressing support for the protests.

The Associated Press contributed to this report.