BAGHDAD >> When tens of thousands of civilians escaped an Islamic State onslaught on the Iraqi city of Ramadi last year, Amir Mishaan and his three children, the youngest barely a year old, were among those who settled into makeshift lives here in the capital.

Mishaan, a Sunni Muslim, got a job at a tiny grocery in a Shiite-majority neighborhood in eastern Baghdad, and waited for the day when he could return home. Closely following news reports in recent weeks indicating that Ramadi had been liberated, though largely destroyed, Mishaan, 45, told his brother he would soon go back, even if he had to live in a tent.

Instead, the Islamic State found Mishaan in the Baghdad grocery on Monday evening and shot him dead. He was one of at least 17 civilians killed in the massacre on a busy commercial street.

“We thought we escaped the terrorists to live peacefully in Baghdad,” Mishaan’s brother, Thamir, said in an interview. “But it seems that my brother was destined to get killed by terrorists.”

It was a week in which the Islamic State, also known as ISIS or ISIL, killed and injured scores of civilians around the world — Germans visiting tourist sites in Istanbul; foreigners outside a Starbucks in Jakarta, Indonesia; and Iraqis in Baghdad and, later that night, at a cafe in Diyala province, a region mixed with Sunnis and Shiites that was for years torn apart by sectarian violence.

The attacks in Iraq had the most casualties, and were all too familiar. Long before the rise of the Islamic State, its predecessor group, al-Qaida in Iraq, was a guerrilla force that inflicted terror on almost a daily basis, especially in Baghdad.

So after a recent shift in the world’s focus to the Islamic State’s seizure of territory in Iraq’s north and west, Monday’s attack created a back-to-the-future feel. Any celebration of military gains against the Islamic State — such as in Ramadi, the capital of Anbar province, where Iraqi forces backed by heavy U.S. air power managed to oust the group from much of the city — is tempered by a fear of the re-emergence of guerrilla tactics that paralyzed this city for so long.

“For the last period, when ISIS was controlling Anbar, Baghdad was safer,” said Faraj Yalda, who works at an appliance shop in the same neighborhood as Mishaan’s store. “As soon as the security forces launched an offensive in Ramadi, ISIS resumed attacking people in Baghdad.”

Baghdadis are worried because the military successes have not been underpinned by progress in solving the issues that allowed the Islamic State to establish roots in Sunni areas in the first place. Political alienation from the Shiite-led government persists, along with a justice system that has allowed the widespread detention of young Sunni men, many without charges, and the continued exclusion from public life of anyone with connections to the Baath Party that reigned during the time of Saddam Hussein.

Prime Minister Haider al-Abadi rose to power in 2014 with strong American backing under the belief that he would forge a political accommodation with the country’s Sunnis — seen as the only long-term route to eradicating the Islamic State. But there is very little progress to point to. As one diplomat in Baghdad put it, speaking on the condition of anonymity as a matter of protocol, “he’s done nothing.”

The attack Monday night in Baghdad involved several suicide bombers who exhausted their arsenals of grenades and guns before detonating their explosives. The next day, a shopkeeper named Hussein Hashim described the terrorists as “well-dressed, good-looking young men who were probably under the age of 30.”

By Friday, much of the street was back in gear.

“We clean up our shops, we take the casualties away, then we resume our lives the next day,” said Ayman Raheem, 19, who works in a women’s clothing shop at a shopping mall that was among the militants’ targets.

But up and down the street, death remained in the air. At a barber shop, a boy and his father were killed. At a furniture shop where several of the victims died, Mustafa Abdul Hussein narrated what had happened, using video from his cellphone to back him up.

He pointed to a street corner to his left, where a friend nicknamed Aboodi was killed while sitting in the blue minivan he used to deliver furniture.

In his own shop, Hussein stood at the spot where victims had fallen, and showed their bloodied bodies on his phone. One, he said, had been learning to teach Arabic at a local college, and died clutching a textbook.

Abdul Hussein Hassan, his father and the owner of the shop for nearly 40 years, was focused on the sidewalk. That was where he had spent many of his days sitting with his friend Abu Ahmed, who owned a kitchen store a couple of doors down and was gunned down Monday night.

“We would sit down out there every day in the morning and drink tea, from morning to evening,” Hassan said. “For 20 years.”

He went on: “There was no military installation here, no government building. They just deliberately meant to kill as many innocent civilians as possible, and terrify the people.”

The father of Ali Mushin, 13, said his son had asked him on Monday morning for money to buy school supplies. Ali was killed before he made it to the stationery store.

“When I went to the hospital to receive his body,” his father said in an interview later, “I found the money still in his pocket.”

The night of the Baghdad attack, the new-old terror also struck Diyala province, where nearly two dozen people were killed when an explosion ripped through a cafe in Muqdadiya, a hardscrabble farming community. Men had gathered to watch a soccer game on television, play dominoes or just chat and drink tea. A subsequent suicide bomber struck as security forces and ambulances arrived.

Like the attacks in Baghdad, Istanbul and Jakarta, this one was also claimed by the Islamic State, and in the days afterward Sunni mosques in Diyala province were sacked and several more people killed in what were widely believed to be revenge attacks carried out by the Shiite militias that are the dominant authority in the area.

“ISIS wants to open a new front in the liberated areas through causing tensions and to use its sleeper cells,” said Karem Abdullah Sadeeq, 34, who suffered a shrapnel injury in the cafe. “The sectarian violence will create new fighters who will join ISIS and make the Sunnis think that it is better to live under ISIS than the militias.”

Among the victims in Baghdad was Ali Mukdad, 20, whose brother said he was trying to build a body like Arnold Schwarzenegger’s and hoped to find a job. Mukdad had fallen in love with a cousin, the brother recalled, but because “he was poor and because he had no money, she refused to marry him.”

On Facebook, Iraqis have been sharing photos of loved ones lost, like a boy named Ali, who is shown holding a soccer trophy. “He is my schoolmate,” a friend wrote. “He went with his family for shopping to prepare for his brother’s wedding. They were all killed. I won’t forget you, Ali.”

© 2016 The New York Times Company