Iranian authorities have arrested a number of people allegedly involved in the murder of the country’s top nuclear scientist last month near Tehran, a parliamentary adviser told an Iranian state broadcaster on Wednesday.

The adviser, Hossein Amir Abdollahian, did not say how many people had been arrested in connection with the death of scientist Mohsen Fakhrizadeh and did not reveal their identity, according to Al Alam News Agency.

“Those involved in this attack, some of whom have been identified and even arrested by security services, cannot escape the judiciary,” said Abdollahian, a former deputy foreign minister who is now an adviser to the President of Parliament. after a transcript of the interview. He added that the authorities would “react firmly to them and make them regret their actions”.

According to American and Israeli officials, Fakhrizadeh was seen as the driving force behind Iran’s secret nuclear weapons program, and the brazen assassination left Tehran in shock and embarrassment. The scientist was ambushed on a country road, although conflicting reports about the conduct of the assassination exposed tensions between rival factions in the Iranian government as each tried to shift the blame.

Shortly after the murder, at least three officials said Israel was behind the attack, and since then Israeli officials have all but publicly acknowledged the responsibility.

It remained unclear how much the United States might have known about the operation in advance, but the two allies have long exchanged information about Iran, particularly its nuclear program.

Mr Abdollahian said that the Iranian authorities believed the Israelis had help coordinating the assassination of Mr Fakhrizadeh, adding “there is no doubt” that there was also American involvement.