Iran has executed three men accused of killing police officers during anti-government protests in January, state media say, marking the first hangings related to the demonstrations.

Among the men was teenager Saleh Mohammadi, a member of Iran's national wrestling team, sources have told CBS, the BBC's US partner.

The executions took place on Thursday morning local time in the northern Qom province after the Supreme Court upheld their death sentences, Iran's Tasnim news agency reported.

The nationwide protests, which began in December and intensified in January, were met with a violent crackdown by the Iranian authorities. Rights groups say thousands of people were killed.

Tasnim, a semi-official news agency associated with Iran's Revolutionary Guard Corps (IRGC), reported that Mohammadi, Mehdi Ghasemi, and Saeed Davoudi were found guilty of killing two police officers in separate attacks in Qom.

The three were also convicted of moharebeh - waging war against God- one of the charges Iran uses to issue death sentences for protesters and opponents of the Islamic Republic. Rights groups allege that the men confessed under torture and were executed without a fair trial.

Their deaths came a day after Iran executed a dual Iranian-Swedish national, Kouroush Keyvani, who was hanged after being convicted of spying for Israel.

The recent protests, which reportedly spread to 180 cities and towns in all 31 provinces, were sparked by anger over the collapse of the Iranian currency and rising cost of living, quickly transforming into calls for political change.

The violent crackdown resulted in at least 7,000 deaths during January alone, according to the US-based Human Rights Activists News Agency (Hrana), with a significant number being protesters and children.