Witnesses said one person was killed, several others were wounded and dozens of people, including women and girls, were arrested on Tuesday.
Taliban authorities did not comment on any casualties or arrests.
Sayed Masoud Hosseini, spokesperson for Herat police, told the state-run Bakhtar News Agency that the gathering in the Jebrail area had "created tensions" and disturbed public order under the pretext of opposing the Islamic hijab, which he described as a religious obligation.
Bakhtar quoted Sheikh Azizur Rahman Al-Muhajir, head of Herat's Department for the Promotion of Virtue and Prevention of Vice, as saying reports that women had been arrested for failing to observe hijab rules were untrue.
He said inspectors carried out their duties by providing guidance and raising awareness about the Islamic hijab.
Since seizing power in Kabul in 2021, the Taliban has imposed sweeping restrictions on women and girls in the war-shattered country, including limits on access to education, employment and sport, drawing widespread international criticism.
Herat, long regarded as one of Afghanistan's most socially and culturally vibrant cities, has undergone significant changes.
Witnesses said the protests erupted when morality officials attempted to arrest women opposing the mandatory dress requirements.
Some residents said officials targeted women who were already observing the required dress code, which includes fully covering the face and body.
Video, unverified by Reuters, showed armed officials breaking up the demonstration, which included fully veiled women among the protesters. In one clip, people ran for cover as gunshots were heard in the background.
On Monday, the UN Assistance Mission in Afghanistan said it was concerned by reports of women detained in western Afghanistan for allegedly failing to meet dress requirements. The mission urged Taliban authorities to respect freedom of movement and equality before the law.
The Taliban says it respects women's rights in accordance with its interpretation of Islamic law.
