The French were responding to Iran saying they are working on advanced centrifuges for uranium enrichment Meanwhile, another French academic was detained in Iran PARIS: France demanded on Wednesday that Iran refrain from entering a new phase of “especially worrying” reductions to Iran’s obligations to a 2015 nuclear deal with world powers. “Iran must abstain from crossing an especially worrying new phase of new measures that could contribute to an escalation in tensions,” French foreign ministry spokeswoman Agnès von der Muhll told reporters in a daily briefing. She was responding after Iranian President Hassan Rouhani said on Monday that Tehran was working on advanced IR-9 centrifuges for uranium enrichment. Those centrifuges do not appear in the 2015 accord. Meanwhile, France’s government denounced Roland Marchal’s unexplained detention as “unacceptable,” and colleagues called Wednesday for his release. Marchal, a sub-Saharan Africa specialist at Paris university Sciences Po, was arrested in June when he traveled to Iran to visit his romantic partner, Fariba Adelkhah, according to Sciences Po professor Richard Banegas, who has worked closely with him. It"s unclear what charges Marchal faces, but Banegas told The Associated Press that he and colleagues consider him “an academic prisoner.”