Iran has executed three men charged in connection with political protests this January, authorities said, the latest in a wave of hangings against the backdrop of the war against the US and Israel.

Iranian authorities have carried out executions on a near-daily basis in recent weeks, in what activists have denounced as a bid to instil fear in society at a time of international and domestic tension.

Mehdi Rassouli, Mohammad Reza Miri and Ebrahim Dolatabadi, all considered political prisoners by human rights organisations, were executed after being convicted over unrest in the eastern city of Mashhad in January, the judiciary’s Mizan news agency announced on Monday.

It was not specified when or where they were executed. But the US-based Human Rights Activists News Agency (Hrana) said Rassouli, 25, and Miri, 21, were hanged at dawn on Sunday at the Vakilabad prison in Mashhad.

The protests began in December, partly as a result of grievances over the Iranian economy but intensified into nationwide rallies against the Islamic regime, peaking as mass demonstrations on the nights of 8 and 9 January.

Rights groups say thousands were killed in a crackdown by security forces; while authorities have blamed “rioters” whom they claim were backed by the US and Israel.

Mizan said Rassouli and Miri had been responsible for the death of a member of the security forces and described Dolatabadi as one of the “instigators” of the unrest in Mashhad.

But Norway-based NGO Iran Human Rights described the three as political prisoners who had been sentenced “after unfair trials in the revolutionary courts”. It said that since executions resumed in March during the war against the US and Israel, Iran had executed 24 political prisoners.

Mahmood Amiry-Moghaddam, the director of IHR, said: “The international community, especially the European Union, must respond decisively to this ongoing wave of executions.

“Unless the political cost of these executions is raised through clear and strong international reactions, there is a serious risk of daily executions continuing in the weeks and months ahead.”

In a statement on 1 May, Amnesty International said the international community must “not stand idly by while the Iranian authorities continue to escalate the arbitrary execution of political dissidents and protesters to instil fear”.

Amnesty said it had documented cases of 13 of the men whom it said had been subjected to torture and “convicted in grossly unfair trials that relied on forced ’confessions’ and lasted a few hours”.

Iran is the world’s most prolific executioner after China, according to rights groups, and last year it hanged at least 1,639 people, according to figures from IHR.