Iranian security forces opened fire at demonstrators in the city of Muhammarah in Khorramshahr during mass protests over water shortages, injuring several protesters, as reports said some of them were killed despite a denial from the authorities.
The protesters set fire to rubbish bins and damaged public property, according to state-run IRNA news agency.
IRNA quoted Interior Minister Abdolreza Rahmani Fazli as saying that just one person was injured in a "confrontation involving shots".
Iranian authorities held the protesters responsible for the violence.
"The statements saying numerous people were killed are false," Fazli said during a press conference.
"Our effort is to bring these protests to an end as soon as possible with restraint from police and the cooperation of the authorities, but if the contrary takes place, the judiciary and law enforcement forces will carry out their duties," he stressed.
The unrest erupted after some 500 people, mostly youth, gathered at a main square in the city to protest against pollution that is seeping into the drinking water network, IRNA reported.
Since the beginning of the year, several protests in Iran have been triggered by water, a growing political concern over a drought that residents and analysts say is exacerbated by mismanagement.
Gun shots could be heard in several videos of the protests circulating on social media in Muhammarah.
According to IRNA, there have been several protests against water pollution in Muhammarah and the neighboring city of Abadan over the past three days.
State television showed banks with broken windows and footage appearing to show an identified demonstrator armed with a rifle.
Police said they fired tear gas as protesters set fire to a bridge and a park surrounding a museum about the Iranian-Iraqi war in the 1980s.
