The five attacked Muhsin Mirdamadi, head of parliament’s Foreign Affairs and National Security Commission, in the central city of Yazd on Friday.

Parliament Speaker Mahdi Karrubi said on Sunday the attack was an insult to parliament. Newspapers showed a bruised Mirdamadi with a bandaged face, receiving a check-up from doctors.

February’s elections will test whether Iran’s voters have lost patience with the country’s embattled reformists who, despite controlling parliament, have largely failed to overcome objections from the Islamic Republic’s powerful conservatives.

Conservative camp loyalists who accuse reformists of selling out to the West, have disrupted reformist speeches in the run-up to elections.

Mirdamadi was quoted by a reformist daily as saying that 40 people had attacked him while he was delivering a speech. He thought one of the assailants shot into the air.

“The close we get to the elections, such incidents are done to enflame the political atmosphere... those who did these things have powerful supporters,” he said.

The official IRNA news agency reported the governor-general of Yazd saying 17 people had been summoned in connection with the assault.