Violence has returned with a vengeance to Iran's restive province of Sistan-Baluchistan.
In less than two weeks, 14 Iranian border guards have been killed, 16 Baluch "bandits" hanged in retaliation, and a state prosecutor assassinated.
The region's judiciary chief, Ebrahim Hamidi, was quoted by state media as saying the November 6 slaying of Mousa Nuri, the state prosecutor in the southeastern city of Zabol, had no connection to the recent hangings.
But in claiming responsibility for Nuri's assassination, a little-known Sunni extremist group, Jaish al Adl, said it was in retaliation for the October 26 hangings of the 16 Baluchi death-row prisoners.
Nuri and his driver were gunned down in front of a hospital in Zabol, which is located close to Iran's borders with Afghanistan and Pakistan.
In a statement posted the same day on its website, Jaish al Adl said Nuri and Mohammad Marzieh, the chief prosecutor in Zahedan, the provincial capital, had sent hundreds of "innocent young Baluchis" to the gallows, including the 16 Sunnis who were executed in October.
The 16, identified by Iranian officials as "bandits linked to groups hostile to the state," were already on death row. But their hangings came just a day after 14 Iranian border guards were killed near the city of Saravan, which lies 270 kilometers to the south of the provincial capital across the border with Pakistan.
Zahedan chief prosecutor Marzieh said the 16, who had been convicted of extremism and drug trafficking, were executed in retaliation for the October 25 border-guard slayings.
Jaish al Adl, or the "Army of Justice", has also claimed responsibility for the border-guard killings, saying it was in retaliation for the "cruel treatment" of Sunnis in Iran and the "massacre" in Syria it claims is being carried out by Iran.
Sistan-Baluchistan is one of the poorest regions of Iran, and the majority Sunni population there often complains of discrimination and marginalization.
'Both To Blame'
Abdol Sattar Doshoki, a Baluchi political analyst who heads the U.K.-based Centre for Baluchistan Studies, says that both the Iranian establishment and militant groups are to be blamed for the latest cycle of violence.
"On the one hand, security, intelligence, and judiciary officials in the region believe they can bring security to the province of Sistan-Baluchistan through the gun barrel or the noose. On the other hand, extremist groups welcome violence and believe that they can reach their goals through violent means."
The region is known as a route for smuggling drugs from Afghanistan to Europe, and in recent years has seen clashes between Iranian troops and drug traffickers that have resulted in the deaths of some 4,000 security personnel.
Clashes have also been reported with insurgents, particularly the Sunni militant group Jundullah, which has been blamed for a number of deadly attacks and suicide bombings that targeted civilians and security forces in Sistan-Baluchistan.
Abdolmalek Rigi, the leader of the extremist group, was executed by Iran In 2010. Jundullah, or "Soldiers of God," claims it is defending the rights of Sunnis in Sistan-Baluchistan.
A TV grab shows captured Iranian Sunni militant Abdolmalek Rigi speaking in a taped statement in 2010 prior to his execution.
Analyst Doshoki says the recently founded Jaish al Adl is pursuing the same path as Jundullah.
"They're the remnants of the group, Jundullah, and they carry on the same method under the name of Jaish al Adl," he says.
Iran's Fars news agency, which is affiliated with the Islamic Revolutionary Guards Corps (IRGC), said last week in a report that "intelligence assessments" show that Jaish al Adl was formed by one of the separated branches of Jundullah.
The recent killing of the border guards, which Jaish al Adl claims was carried out by several of its members, and the subsequent executions by the Iranian government have been condemned by many Iranians.
In an open letter issued on November 5, some 400 academics, political activists, and human-rights defenders blasted the "terrorist attack" by Jaish al Adl, while expressing concern over the "medieval-style executions" of the 16 Baluch prisoners.
The letter said the killings, by both sides, contributes to the cycle of violence in the province. The signatories called on the Iranian establishment to respond to the "legitimate demands" of the country's minorities.
Sebastien Brabant, the spokesman of EU foreign policy chief Catherine Ashton, condemned the executions in an October 31 interview with RFE/RL.
"The European Union has a very strong and principled position against the death penalty and of course we reiterate our call on Iran to halt all pending executions and to introduce a moratorium on this cruel and inhuman punishment," Brabant said.
A U.S. State Department official said rights groups have so far documented 400 executions in Iran in 2013.
"Washington strongly opposes executions in the absence of due process," the official said in an email to RFE/RL.
RFE/RL correspondent Rikard Jozwiak contributed to this report