Almir Arruda rode his bicycle quickly across the City of God slum in Rio de Janeiro when he heard there was shootout between drug traffickers and police near his 4-year-old daughter’s preschool.

Arruda, a 43-year-old unemployed construction worker, arrived to find children and teachers lying on the floor to protect themselves as the pounding of bullets continued nearby. He scooped up daughter Jamile, who look terrified, and they rode the bike a few blocks until Arruda stopped to wait out the shooting — and started crying.

“If it hits me I don’t care, but what if it hits her?” Arruda said, talking about stray bullets through tears and over the sounds of gunshots close by. “I feel like a prisoner in the community.”

In this June 12, 2017 photo, Almir Arruda wipes tears as he waits for a shootout between drug traffickers and police to stop, as he stands over his four-year-old daughter Jamile in the City of God slum of Rio de Janeiro, Brazil. (AP Photo/Leo Correa)

In this June 12, 2017 photo, Almir Arruda cries as he waits with his four-year-old daughter for a shootout to stop between drug traffickers and police in the City of God slum of Rio de Janeiro, Brazil. (AP Photo/Leo Correa)

Amid a sharp increase in violence in favelas, or slums, millions of Rio residents are facing daily stresses akin to those in a war zone. Heavily armed drug traffickers battle for control of many favelas, and violent police operations add to the death toll and sense of fear. Last year, 920 people died during police raids or patrols in Rio state, more than double the 413 in 2013, according to Rio’s Public Security Institute. And this year’s figure is up by almost 60 percent over 2016.

To document the psychological impact of the violence on favela residents, an Associated Press team spent eight days with two families in the City of God, a slum of about 50,000 residents made famous by the 2002 Oscar-nominated film of the same name and visited six years ago by then U.S. President Barack Obama.

While there, the AP witnessed children, even toddlers, talking about violence in their community, mothers forcing their children to take cover during police patrols and a man recovering after being shot. The roar of gunfire was often present, prompting residents to break up activities when they believed the skirmish to be particularly close.

Different than hundreds of other Rio favelas that grew out of squatter communities, City of God was built in the 1960s as a housing project for people who had been forced out of other favelas. It sits just a few miles from the Olympic Park in upscale Barra da Tijuca. Despite proximity to wealth, government services are practically non-existent. Parts of the slum are covered with garbage and the stench of sewage permeates the air.

In this June 6, 2017 photo, open sewage is covered by trash near homes in the City of God slum of Rio de Janeiro, Brazil. (AP Photo/Leo Correa)

While teeming with residents, even during the day the streets are often empty because violence can erupt at any moment — residents even complain that police operations happen while children are in school.

When residents leave the slum to go to work, relatives and friends stay in touch via texts. They let them know if there has been a shooting, in which case they have to wait until it’s over to return. “Fogo Cruzado,” or “Crossfire,” is a free app created by Amnesty International Brazil that helps Rio residents track shootings in real time by combining crowd-sourcing data and monitoring social media.

On a recent Friday evening, a military police tank suddenly appeared. Shouting to alert her family, Thaisa da Silva Ribeiro grabbed 4-year-old Isaac, who was playing in the door of their building, and brought him inside. Isaac’s sister, 2-year-old Isadora, looked terrified.

“It’s not possible to get used to this, but unfortunately this is the routine in City of God,” said Ribeiro, who is pregnant.

Minutes later, Isaac cried about the incident while Isadora hugged her brother and tried to calm him down.

In this June 9, 2017 photo, Thaisa da Silva Ribeiro calms her four-year-old son Isaac, right, and two-year-old daughter Isadora as her husband Silvio Cesar Soares Gonzaga sits with them after a military police tank drove through their neighborhood i… — In this June 9, 2017 photo, Thaisa da Silva Ribeiro calms her four-year-old son Isaac, right, and two-year-old daughter Isadora as her husband Silvio Cesar Soares Gonzaga sits with them after a military police tank drove through their neighborhood in the City of God slum of Rio de Janeiro, Brazil. (AP Photo/Leo Correa)

In war zones, children and adults can suffer post-traumatic stress disorder, anxiety, nightmares, insomnia and other psychological disorders.

Many of those symptoms are being observed in residents of slums, particularly children, according to health experts at Fiocruz, one of Brazil’s top research institutes, which is conducting a large study on health issues related to urban violence in Rio.

Leonardo Bueno, one of the researchers, says that anxiety and depression from the violence are compounded by the feeling the state has abandoned poor areas.

“All of that increases the level of illness in an area,” he said.

Fueling the tension is a widespread belief among favela residents that police see them all as criminals and will be quick to rough them up without cause.

Like Ribeiro, 45 percent of favela residents fear that police will confuse them with criminals and 75 percent believe the police act more violently in favelas than in wealthier areas, according to a survey by the Center for the Study of Safety and Citizenship at Rio’s Candido Mendes University.

Alexandre Henrique da Cruz Correia, a 29-year old father of three, was recently shot while walking from his grandmother’s home to his own.

“I passed by the police, and by the time I got to the end of the street I had been shot twice,” said Correia, showing where one of the bullets was still lodged in back of his left hip. “I have no idea where it came from.”

In this June 10, 2017 photo, Alexandre Henrique da Cruz Correia holds an X-ray showing a bullet lodged in his left hip in the City of God slum of Rio de Janeiro, Brazil, after he was recently shot while walking home from his grandmother's. (AP Photo… — In this June 10, 2017 photo, Alexandre Henrique da Cruz Correia holds an X-ray showing a bullet lodged in his left hip in the City of God slum of Rio de Janeiro, Brazil, after he was recently shot while walking home from his grandmother's. (AP Photo/Leo Correa)

Stray bullets are such a concern that some families have plans of what to do during a shooting.

Suzi Souza dos Santos, 26, and her two girls and husband live in a small wooden house in one of the slum’s poorest areas. During a shootout, the family goes to a neighbor’s house made of bricks.

“We have nowhere else to go when we are caught in the crossfire,” she said.

Residents say a crushing economic crisis is fueling the sense of desperation. Unemployment in Rio de Janeiro state more than tripled from 4 percent in 2013 to 13 percent in 2016, leaving thousands in abject poverty.

“Rio is a chaos,” said Silvio Cesar Soares Gonzaga, a 46-year-old former drug dealer who became an evangelical pastor. “The violence has polluted it.”

For more than 20 years, Ana Regina de Jesus has been providing free meals four days a week. On a recent day, only about 60 of the usual 150 showed up because of a nearby shooting. During the meal, another shooting erupted, prompting some of the diners to put down their silverware and listen closely.

“These things should not happen,” said Jesus, 58. “But what can we do?”