Iran's “shameful” human rights record has been condemned by Foreign Secretary William Hague.
His comments follow the death sentences passed on five members of the Ahwazi Arab community last month, weeks after the secret execution of four others from the minority for "enmity against God".
Mr Hague warned Iran's actions would not go unchallenged by the international community and said the abuses added to the regime's isolation.
Mr Hague said Tehran had shown an "utter disregard for human rights" in a number of cases, including the death penalty carried out against Safieh Ghafouri, a woman convicted of murder, who was reportedly subjected to abuse and mistreatment including rape while in custody.
The Foreign Secretary said: "I am deeply disturbed by the human rights abuses perpetrated by Iran in recent months.
"The torture and sentencing to death of Mohammad Ali Amouri, Sayed Jaber Alboshoka, Sayed Mokhtar Alboshoka, Hashem Sha'bani Amouri and Hadi Rashidi, from the Ahwazi Arab minority, comes less than a month after the secret execution in June of four other members of this minority group. This sets a very worrying trend.
"The shocking mistreatment in prison of Safieh Ghafouri and her sudden execution is yet a further example of Iran's utter disregard for the most fundamental human rights.
"Sadly, these are not isolated incidents and many other Iranians are currently suffering at the hands of their government.
"Iran's continued, widespread persecution of ethnic minorities, human rights defenders and political prisoners is a disgrace and stands as a shameful indictment of Iran's leaders.
"The Iranian government should know that its systematic attempt to curtail the freedom of its citizens will not go unchallenged by the international community and only adds to its isolation.
"I call on Iran immediately to commute these death sentences, to stop torturing its citizens and to end the systematic persecution of its ethnic minorities."