BAGHDADI, Iraq — As he hunted for a seasonal delicacy, Mohaned Salah Yasseen scanned the ground intently, searching for places where the soil is cracked and slightly raised — the telltale sign a desert truffle lies below.
So he failed to notice the two pickup trucks, driven by men in military uniforms, until they were almost upon him.
“They ordered me to get into the truck,” said Mr. Yasseen, a 31-year-old pharmacist. “I thought about saying no, but they were armed.”
As he climbed in, he became the latest victim in a new campaign by the Islamic State.
Driven out of most of the territory it controlled in Iraq and Syria, the group has gone underground, its remaining fighters in Iraq carrying out sporadic attacks.
Since late January, they have been kidnapping and, in some cases, executing Iraqi truffle hunters, mostly in the deserts of western Anbar Province. The Iraqi security forces confirmed the kidnapping of 44 truffle hunters this year, and more have probably gone unreported.
The abductions are only a fraction of the Islamic State attacks now taking place in Iraq, where every day brings one or more reports of a checkpoint shooting, skirmish or kidnapping. But the attacks on truffle hunters reflect a renewed emphasis on inciting sectarian tensions.
While Sunni Muslim truffle hunters typically pay a ransom to win release, as Mr. Yasseen did, Shiite Muslim truffle hunters never get that chance. They are killed.
The Islamic State considers Shiites infidels, and since its inception the group has killed them and destroyed their mosques.
Iraqi intelligence and military authorities view the group’s treatment of hostages as an attempt to incite the kind of sectarian strife that tore Iraq apart from 2003 to 2008, after the fall of Saddam Hussein, and was reprised from 2012 to 2014.
Abu Ali al-Basri, the director general of Iraqi intelligence, said his fear was that the killings could goad Shiite politicians into verbally tarring Sunnis collectively. That message would then be amplified by the media and could set off a cycle of violence.
The kidnappings are a way for the Islamic State, also known as ISIS, to raise money and signal to the civilian population it remains a potent force. Some 5,000 to 6,000 Islamic State fighters remain in Iraq and Syria, according to Iraqi officials, who consider the group a manageable threat.
Despite the danger, desert truffle hunters seem undeterred. The delicacy is prized and can bring up to $6 a pound in local markets.
The desert truffle is far less fragrant and flavorful than its European counterpart, but is valued in Iraq for its meaty texture and subtle taste. Known in Iraqi Arabic as “chimay,” almost every family in this region of Iraq has a favorite recipe.
In local lore, chimay is a gift from God. One story goes that Mary, the mother of Jesus, asked for meat without bones, and God gave her chimay.
Mr. Yasseen had driven several hours into the desert from his home in Bhagdadi to a place so idyllic and remote it was hard to imagine it could be dangerous. Truffle hunting is a favorite activity of many families in western Iraq during the cool winter days when the arid landscape is briefly verdant.
“It was a flat area, beautiful, very green, nothing but earth and sky,” Mr. Yasseen said.
After his captors blindfolded him and five cousins who had been hunting truffles with him, they seemed surprisingly eager to make sure their hostages knew who had seized them.
“They asked us: ‘Do you know who we are?’” Mr. Yasseen said. “Then they said: ‘Just to let you know, we are the Islamic State.’”
Mr. Yasseen recalled immediately thinking “I’m dead. This is it, they will kill me.”
Instead, he and his cousins were driven to the mouth of a tunnel that led into a small underground room where there was already another group of captives.
The Islamic State fighters did not speak, but brought food and invited them to pray.
The next day, an Islamic State operative came to question the first group of captives, but he seemed to already know facts about them and ticked off personal details, like where one man worked and what his political sympathies were.
Mr. Yasseen suspected that the Islamic State had agents embedded in the local government who could look up such details.
In one case, the Islamic State inquisitor accused a man of lying about his occupation, according to a captured elementary school principal.
“We found out you work with the civil defense, and so your sentence is death,” the inquisitor said. (So far, the only Sunni truffle hunters killed have been off-duty police officers.)
“It’s true, I used to work for civil defense,” the accused man said, “but then I quit and now I am a butcher.”
The school principal, Salah Malik Flayah, 62, said he rose to the man’s defense: “He is telling the truth. I know him. He is my neighbor and he is a butcher.”
The butcher’s life was spared.
Mr. Flayah was told he’d have to pay $50,000 for his freedom, an inconceivable amount on his $1,200 a month salary. Eventually, the price dropped to $20,000. Some were asked to pay $10,000. For Mr. Yasseen’s group, the ransoms were similar.
Hamza Kadhim al-Jubori, 42, a Shiite farmer, had a very different story. The remote area where he and two of his brothers, his nephew and two neighbors went to gather truffles was about 65 miles south of where Mr. Yasseen was kidnapped.
Like Mr. Yasseen, they were captured by men wearing military uniforms and were taken through an underground tunnel into a room where there were other captives. The similarities ended there.
The extremists brought Mr. Jubori’s group only a single date and a half cup of water each while the Sunni captives were given a full meal. The Sunnis were invited to pray, but not Mr. Jubori and his relatives. The Sunnis’ handcuffs were removed, but not those of Mr. Jubori’s group, whose shoes were also taken.
An Islamic State operative called each of the Sunni captives’ names, noting their hometowns, but when he turned to the Shiites, he just said “ apostate,” a death sentence.
During the night, the fighters drove Mr. Jubori and his companions into the desert. An M-16 rifle was between the Islamic State driver and the guard in the passenger seat.
Fearing he would be killed at any moment, Mr. Jubori said he pulled at the ropes that bound his hands until he freed them, whispering to his brother to do the same.
“I just was hoping to survive, to live. I watch a lot of American films, Jackie Chan, Arnold,” he said, referring to Arnold Schwarzenegger. “And I thought maybe I could save myself.”
He and his brother and neighbor grabbed their captors from behind. The driver turned the car off, jumped out and ran into the desert. Mr. Jubori dove into the driver’s seat, turned the key in the ignition but the engine would not start.
He grabbed the M-16, poked it into the other fighter’s stomach and pulled the trigger. Nothing happened. He tried again. Nothing. He later realized he had failed to take off the safety lock.
“I lost hope,” he said. “The car doesn’t work, the rifle doesn’t work, I can’t see anything because we’re driving without lights.”
Terrified, he jumped out of the pick up. “I wasn’t thinking about anyone else, I couldn’t think of anything,” he said. “I was just holding the rifle and running.”
Then other Islamic State fighters in a second vehicle began shooting toward him in the dark. Mr. Jubori flung himself under some desert scrub and lay still until they drove away.
He said he walked for a week before he was rescued by Bedouins, desert nomads, who were out collecting truffles.
Three days later he was home — but without his two brothers and his nephew, leaving Mr. Jubori feeling like he had failed his family. A few days later, they were found shot to death.
“Really, I am eating myself,” Mr. Jubori said, adding that in his tribal culture, leaving behind family members is tantamount to betrayal.
Now in a wheelchair because his feet were badly damaged during his barefoot trek, Mr. Jubori looked bleakly at the M-16 that he had seized.
Usually, it would have been a prized possession.
“I lost two of my brothers, my nephew; all I did was save myself,” he said. “The rifle doesn’t mean anything to me.”
He leaned his head against the wall and began to weep.