Iranian security forces prevented former president and opposition figure Mohammad Khatami from leaving his Tehran home late Wednesday, local media reported. It was the latest sign that regime hard-liners were seeking to crack down on the country's reformists, activists said.

Two opposition-linked news sites said security forces arrived at Khatami's home in the Iranian capital to block him from meeting with political allies, a move that one outlet referred to as "temporary house arrest."

Khatami, a widely popular, pro-reform cleric, served two terms as president, from 1997 to 2005, but was later banned from public appearances after supporting anti-government protests in 2009. An order from a state prosecutor this month tightened those restrictions, according to one of Khatami's lawyers, imposing measures including a three-month ban on receiving political guests.

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The government did not publicly confirm the restrictions. But the incident Wednesday is being cast as part of a broader conflict between pro-reform figures, who have allied with President Hassan Rouhani, and hard-liners in the security forces and judiciary. Those rivalries are likely to be aggravated as tensions rise between Iran and the Trump administration, which has vowed a more aggressive U.S. policy toward Iran, and as Iranian political factions jockey for power.

The Iranian regime "never misses a chance to utilize American antagonism to its own advantage," said Suzanne Maloney, a senior fellow and Iran expert at the Brookings Institution.

On one side are the moderates and reformists, who have pushed for gradual change in the system, including greater political freedoms and more dialogue with the West. On the other side are the hard-line security forces and conservative clerics, who have balked at diplomacy and suppressed dissent.

President Trump's speech on Iran last week, in which he outlined a new, aggressive strategy, gave Iranian hard-liners "the opportunity to crack down against any political force that poses even a notional challenge to the authority and the legitimacy of the Islamic Republic," Maloney said.

This month, an Iranian court sentenced seven reformist lawmakers, including Khatami's brother, to a year in prison for "propaganda against the state." Rights activists have also reported that relatives of late president Ali Akbar Hashemi Rafsanjani were recently banned from traveling abroad.

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But the moves against Khatami — the 74-year-old standard-bearer of Iran's reform movement — are likely to raise the stakes further. Khatami remains highly popular among Iran's youth and urban middle class, analysts said.

His popularity as a reformer "is deeply unsettling to the intelligence and security apparatus of the Islamic republic," said Nader Hashemi, director of the Center for Middle East Studies at the University of Denver. People "look back on his presidency and his reformist agenda with fond memories," he said. "Arguably, he is the most popular politician in Iran today."

Khatami has faced pressures since the nation was hit by mass protests in 2009 after the disputed reelection of then-President Mahmoud Ahmadinejad, a hard-liner, amid claims by activists and others that Iranian leaders had manipulated the vote against reformist Mir Hossein Mousavi. Mousavi and another presidential contender in that race, Mehdi Karroubi, have been under house arrest since 2011.

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In 2015, Iranian news media were temporarily blocked from publishing Khatami's name or image. Still, in May, he defied the ban to endorse Rouhani for reelection. Since then, Rouhani has sparred with the judiciary and commanders of the country's powerful Revolutionary Guard Corps. And this month, he criticized judicial officials for the new restrictions on Khatami, adding to a string of public rebukes by Rouhani against the clerical establishment.

Iran's judiciary is acting like it has "nothing better to do" than summon people for questioning, Rouhani said during a speech at Tehran University on Oct. 7.

Iran's judicial chief, Sadegh Larijani, responded harshly.

"If there's anyone with nothing better to do, it's you, who for the past four years has been defending the nuclear deal so passionately that it seems there are no problems in the country," Larijani said.

Behnam Ben Taleblu, an Iran expert at the Foundation for Defense of Democracies, said Iran's hard-liners are sending a message to those seeking reform.

"Khatami's restricted mobility, which essentially places him under house arrest, carries a message from Iranian hard-liners to reformists," he said. "It says, 'Ultimately, you are dispensable.' "

Brian Murphy in Washington contributed to this report.

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