In an unusual display of public candor, Iranian authorities have said in recent speeches that Islamic State infiltrators are becoming a growing threat to the Islamic Republic.
At least three times in recent months, Iranian officials have spoken about breaking up IS-related terror cells and arresting IS-affiliated militants planning attacks inside Iran.
The claims lack many details, including when the alleged incidents took place, the identity of most suspects and concrete links to IS. And at times, the information has conflicted with other accounts.
But the growing emphasis by Iranian officials on the militant group's possible threat has caught the attention of Western analysts who monitor developments in Iran and offer varying views on the extent of the threat and Iran's aim by speaking publicly about them.
Iran's involvement in Middle East conflicts by helping Shi'ite groups in Iraq and Yemen, and backing President Bashar al-Assad's regime in Syria, makes the nation a natural target for IS and other extremist Sunni groups, experts said.
"The [IS] threat is real and there is no doubt about its significance," Alireza Haghighi, a senior lecturer in global affairs at the University of Toronto, told VOA.
Iran has Revolutionary Guard fighters on the ground in Syria helping Syrian government forces. While mostly targeting rebels, Iranian forces have sometimes tangled with IS fighters in Syria.
With its Sunni brand of extremism, IS sees Iran's Shi'ite majority as an enemy. Islamic State's new spokesmen promised last week that there would be attacks on Iran as well as on the West and Turkey.
Iranian intelligence agencies have foiled several alleged plots by IS followers to attack Tehran and other major cities in the country, officials said.
Iran Intelligence Minister Mahmoud Alavi said in August that agents "spotted and thwarted more than 1,500 young people who intended to join" IS. He said in October that agents disrupted a bombing plot targeting the Shi'ite religious commemoration of Ashoura inside Iran.
Iranian officials say IS threats have increased since mid-November after a deadly attack claimed by IS on Shi'ite pilgrims in Iraq, which left at least 80 people dead, including several Iranian citizens.
Last week, Alavi said a team of Iranian intelligence troops, known as Ettelaat, killed a group of IS militants who attempted to cross the Iranian border from Iraq.
Alavi also claimed that a prominent IS figure of Iranian origin was killed while leading the group to carry out attacks inside Iran.
"An [IS] leader known as Abu Aisha al-Kurdi, together with many other militants, was killed by the Ettelaat forces as they were trying to cross the Iranian border," Alavi said, speaking at a religious ceremony in Karaj, 35 kilometers west of Tehran.
Alavi's statement, however, contradicted several news accounts that reported Kurdi's death months earlier. In April, the Iraqi military said that it had killed Kurdi during a battle in the town of Makhmour in northern Iraq.
The Kurdish news agency Rudaw later reported that Kurdi had been killed during a confrontation with Iranian intelligence forces in April near Javanrud in western Iran.
Kurdi, whose Iranian name is Mohammad Ebrahimi, comes from a Sunni Kurdish family in Kamyaran in western Iran. He reportedly traveled to Iraq in September 2014 with his wife and daughter to join IS, Iraqi news reports said.
Attempting to make link
Some analysts said Tehran might be attempting to show a link between IS and Iranian Kurdish rebels who have been battling with Iranian troops for years for regional autonomy in western Iran.
Ethnic Kurds make up nearly 9 percent of Iran's population of 80 million people. They are largely Sunni Muslims and have long desired more autonomy from Tehran, calling for cultural and political rights.
In announcing the death of an Iranian Kurdish IS leader, Tehran is using the news "to justify pressure over Kurdish activists in Iran," said Hazhar Rahimi, an analyst at the University of Soran in the Kurdish region of Iraq.
Hundreds of volunteer Iranian Kurds have bolstered Kurdish forces in Syria and Iraq in recent months in the fight against IS.
Tehran has registered its displeasure with Kurdish officials over the use of Iranian Kurdish volunteers in battle, even though most volunteers are not linked with Iranian Kurdish rebels.
In focusing on IS in public speeches, the Iranian regime may also want to show the Iranian people that it is getting tough on militancy, analysts said.
Iranian officials "play the IS card whenever they feel they need it, whether it is for domestic purposes, like showing how bold they are, or to show international players how their importance can change the equation of the game," said Rasool Nafisi, an Iranian affairs expert in Washington.
Michael Horowitz, a Middle East security analyst, said as Iran faces increasing casualties on the battlefront in Syria, it "has also been able to rally domestic support for its operations outside the country by pointing to the possibility that IS would sooner or later attack in Iran itself."
"This was the case, for instance, after the Paris attack, when [intelligence chief Alavi] said this should serve as a warning to Tehran," said Horowitz, director of intelligence at Prime Source, a Middle East-based geopolitical consultancy.