Iran executed three young men Thursday, including a 19-year-old star wrestler, prompting human rights groups to warn of a potential wave of executions targeting participants in nationwide protests earlier this year.

Saleh Mohammadi, 19, along with Mehdi Qasemi and Saeed Davoudi, were hanged in Qom, south of Tehran, according to state media. The three were convicted on charges of "moharabeh" or "waging war against God" for allegedly killing two police officers during protests in the city. Mohammadi was a bronze medalist in youth freestyle wrestling and had competed internationally.

The executions mark the first death sentences carried out against individuals arrested during massive protests that erupted in late December and peaked in early January. The demonstrations prompted what rights groups describe as the deadliest crackdown by Iranian security forces since the Islamic Republic's establishment in 1979.

Amnesty International said the convictions came through "grossly unfair trials" that relied on confessions extracted by torture. The organization reported that Mohammadi was beaten during detention and had one hand broken, and that he denied the charges and retracted his confessions in court, claiming they were coerced.

Human rights organizations estimate that at least 27 people arrested during the protests currently face death sentences, while approximately 100 others face charges carrying the death penalty. The U.S.-based Human Rights Activists New Agency reported that more than 7,000 people were killed during the protests, with over 50,000 arrested in just over six weeks. The Iranian government acknowledged more than 3,000 deaths.

The executions occurred amid ongoing military conflict between Iran and a U.S.-Israeli coalition that began in late February. Rights groups express concern that Iranian authorities are using the executions to deter future protests and maintain control during the external military pressure. Iran Human Rights director Mahmood Amiry-Moghaddam warned that many more "executions of protesters and political prisoners may be imminent."