As Gaza marks three years since the Israeli assault that devastated the Strip and left more than 2,200 Palestinians killed, the psychological effects of the violence linger on.

Children were among the most affected groups; in the 50-day onslaught, the Israeli army killed 500 children. The bombing campaign, which started in July and ended in late August 2014, caused outrage and spurred international protests as images of dead children flooded social media.

The United Nations estimates that, currently, more than 300,000 children are in need of psychosocial support.

Three years after the war, Al Jazeera speaks to the families of three children who were psychologically affected after surviving attacks or by the death of their siblings, relatives and friends.

Amir Ibrahim Al Reqeb, 9, Khan Younis

Every time Amir hears the sound of Israeli warplanes buzzing in the sky, or the sound of thunder in winter, or a loud bang, he rushes to his parents for protection.

Last July, on the first night of Eid al-Fitr, an Israeli attack hit near Amir's home in the town of Bani Suhaila, in Khan Younis, in the southern part of the Gaza Strip.

His uncle and two of his neighbours were killed in the attack. Thirty-seven others were injured, including Amir.

First responders could not find Amir easily - they thought he was dead, but later found his body about 100 metres away, covered in sand.

"Amir suffered an injury to his skull and broken bones in his jaw," his mother, Ibtisam, recalls. She then pointed to the shrapnel that injured Amir in different parts of his body, particularly his eye and his lungs. "He lost one of his eyes," she continued in a muffled voice.

Since the war, Amir has become a permanent visitor to hospitals. He endured a series of surgeries in both Israel and the West Bank and spent six months in the ICU, which forced him to leave school.

Ibtisam, 38, devoted her life to Amir. She left her newborn baby, who was born on the same day that Amir was injured – July 27, 2014, to be with Amir, who was transferred to a hospital in Israel three days after he was injured.

Though Amir has steadily recovered from his wounds, the psychological impact of the war has continued to haunt him. He awakes throughout the night, saying he had a nightmare, and can only sleep when his parents are by his side. "He takes his pillow and follows me. He puts his pillow on my lap and sleeps. If he wakes and does not find me or his father next to him, he begins to cry, searching for us."

Zahia al-Qarra, a psychologist at the Gaza Community Mental Health Programme, says the many lingering effects of the war "continue to arouse memories, everpresent within the imagination of the children".

"The end of the war does not mean that children are safe," she told Al Jazeera.

The permanent electricity cuts, and the continuous hovering of Israeli planes, the media and constant talk about a potential imminent war, Qarra explains, lower the morale of children and cause them to be continuously haunted by the trauma.

Muntaser Bakr, 14, Gaza City

Muntaser Bakr sits in the TV room watching the kids' channel, Spacetoon, on what the limited hours of electricity permit him. The picture of his brother, Zakaria, hangs high behind him, along with the pictures of his nephew and two of his cousins.

At 11, Muntaser witnessed one of the most horrific scenes a minor can come across. In one of the most controversial Israeli attacks during the war, Muntaser and seven of his relatives and friends, mostly minors, became the targets of Israeli missiles, while they were playing football on the beach.

Muntaser and three other children from his extended family managed to escape wounded, but four others, including his brother, were killed in the attack.

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Three days after the tragedy, Muntaser awoke from a coma and started shouting: "They're all dead! I killed them, I killed them." He clung to his mother with both hands, before she said: "You did not kill anyone."

Ever since, Muntaser has suffered from post-traumatic stress disorder (PTSD). His days at school have become a distant dream. "He used to sit with his brother, and they would go to school together, play together," his mother said, crying.

Before the war, Muntaser spent most of his time on the beach. But after the war, he stopped going. His mother, Sharifa, says: "The first time he went back to the beach after the tragedy, he spent a long time looking at the sea, and then started crying. He doesn't go back any more."

Muntaser regularly suffers from hallucinations and often murmurs unintelligible words. He also suffers from spasms about three to four times a week. "It happens unexpectedly. He starts screaming and then experiences a spasm, lose consciousness, his eyes roll back, and he starts clenching his jaw. He does not calm down until we take him to a hospital to get an injection".

Doctor Samy Owaida, a psychiatry consultant for children and adolescents, explains that symptoms of psychological trauma manifest themselves in children in a various number of ways.

"The physical can manifest itself through headaches, pain in the abdomen and joints, as well as the illusion of weakness, without any real organic causes," he told Al Jazeera.

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"Behavioural symptoms include becoming introverted or aggressive. They can also cause feelings of insecurity, anxiety, fear and pessimism. Instead of thinking about things that are in line with their innocence and childhood, they start to fear the possibility of another trauma. On the cognitive level, they can start to perform really poorly in school and become distracted."

Since the tragedy, Muntaser has only been back at school once. He fought with one of his colleagues and hit him with a chair, causing his parents to take him out of school.

Malak Abu Jamous, 9, Khan Younis

Malak sits quietly drawing in the Future Home Association in the Khoza'a neighbourhood. She has drawn a variety of things in the past: a plane bombing, a child dying, a demolished house. This time she's drawing a house with an old man standing next to it, "This is my grandfather, Salman, and this is me," she says.

According to a study titled, Psychological Indicators of Drawings by Palestinian Children After the Gaza War, by Dr Jamil Tahrawi and Dr Sanaa Abou-Dagga, both professors of psychological health at the Islamic University of Gaza, 82.3 percent of children surveyed have drawn images related to war.

These include: fighter planes, destroyed homes and mosques, Israeli rockets and missiles, dead Palestinians, various military vehicles, and fighters. The drawings showed fear, terror, and sadness over the those killed and wounded.

When the Israeli army entered the Khoza'a region - which lies to the east of the city of Khan Younis on the eastern border between the Gaza Strip and Israel - over land, they separated the men from the women and children, Malak's mother, Ahlam, recalls.

Ahlam, 33, describes the scenes they witnessed: "We saw dead donkeys and sheep. We saw martyrs with their bodies thrown on the ground, we saw a girl in a wheelchair, her body was on the ground."

"My daughter would cry and scream whenever she saw such things."

Malak used to spend most of her time with her grandfather, Salman, who was killed in the war on Gaza. She remembers him as a kind man: "He was the one who gave me my allowance."

Now, when Malak misses her grandfather, she talks to a photo of him.

"The question that she asks me the most is: 'Will my grandfather come back? When will he come back?'" to which Ahlam responds: "No, he has gone to heaven."

But the answer does not satisfy Malak, who then poses the same question to her father. He answers her indirectly: "Do people who have died returned?" to which Malak responds: "Yes, my grandfather will return."

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Ahlam says that Malak used to be a strong, confident little girl, but has since become introverted and reluctant to interact with others. She suffers from symptoms of PTSD such as headaches, incontinence, and nervous outbursts.

She does unusual things that are hard to comprehend, her mother explains. "One time, she took the kerosene that I had gotten for cooking and spilled it on the bathroom floor." When Ahlam asked for an explanation for what she was doing, Malak didn't answer.

"A few days ago, she woke up at night shouting 'Get away from me!'"

"Wars and their aftermath bring up an important question that children have limited capacity to understand. So this question gets at the identity of the child," says Qarra.

"They ask 'Why was I targeted when I really haven't hurt anyone?'"