Remembering Khan Sheikhoun: Syrian survivors of deadly sarin attack grieve one year on

At least 80 people were killed on April 4 last year, on Yusuf and his wife's anniversary, when war planes dropped sarin gas on his hometown of Khan Sheikhoun in northwest Syria.

The chemical assault on the rebel-held town was one of the most shocking of Syria's seven-year war, causing global outrage and rare retaliatory airstrikes by the US.

"I've been deprived of part of my body, of my soul," says the young widower, breaking into tears as he sits in the garden of his now empty home.

An image of Yusuf holding the lifeless bodies of his 11-month-old twins, Aya and Ahmad, spread around the world in the wake of the attack.

Yusuf also lost his wife Dalal and 16 other relatives, including his brother, nephew and many cousins.

As Yusuf visits the cemetery to weed the graves of his loved ones twelve months on, his grief and anger is still raw.

"I won't be able to start over. I won't forget the past," he says.

Witnesses said they saw people drop to the ground, convulsing violently, some with white foam pouring out of their mouths

'Never forget'

Khan Sheikhoun lies in Syria's Idlib province, the last in the country to remain largely beyond the control of President Bashar al-Assad's regime.

UN war crimes  investigators said they have evidence Syrian government forces were responsible for the deadly attack on Khan Sheikhoun, but the allegations have been rejected by Damascus and its ally Russia.

"We want the international community to take a strong stand... Assad needs to pay," Yusuf says.

The early morning raid last year killed more than 80 people including 30 children, the Syrian Observatory for Human Rights said.

Witnesses said they saw people drop to the ground, convulsing violently, some with white foam pouring out of their mouths.

Ahmad al-Yusuf, 20, lost both his parents and two young brothers, Mohammed and Anwar, on a day he says he will never forget.

His mother had woken him up to perform morning prayers before he headed out to work on his grandfather's land.

After the strikes hit, he rushed back home to find his neighbour sitting on the ground, shaking uncontrollably and incapable of talking, but staring straight at him.

"I'll never forget that day or those details," says the young man with a short haircut, who now runs the family's convenience store on his own.

"I lost all my family – everything that was dearest to me."

He clings on to their memory even as he adapts to his new life alone.

"Whether I'm coming or going at home, I always see them in front of me."

I'll never forget that day or those details... I lost all my family – everything that was dearest to me

World is 'weak'

The deadly strikes on Khan Sheikhoun sparked international condemnation and caused the United States to fire 59 Tomahawk cruise missiles at a Syrian airfield allegedly used in the attack.

But the bereaved residents feel nothing more substantial has been done to hold those responsible to account.

Mohamed al-Jawhara, a 24-year-old, lost his parents, nephew and several cousins.

"It was such a shock. How do you bear seeing them all die in a single day?"

The Khan Sheikhoun attack was yet another low point in seven years of Syria's war, which started in 2011 with the brutal repression of anti-government protests. 

It began when the Baath regime, in power since 1963 and led by President Bashar al-Assad, responded with military force to the peaceful protests demanding democratic reforms during the Arab Spring wave of uprisings. This triggered an armed rebellion fuelled by mass defections from the Syrian army.

According to independent monitors, hundreds of thousands of civilians have been killed in the war, mostly by the regime and its powerful allies, and millions have been displaced both inside and outside of Syria.

The brutal tactics pursued mainly by the regime, which have included the use of chemical weapons, sieges, mass executions and torture against civilians have led to war crimes investigations.

Multiple rounds of UN-backed talks have failed to stem the fighting, and Russia-backed regime forces have instead made significant military gains across the country.

Jawhara expresses frustration at what he sees as the insufficient response of the international community in holding Assad to account.

"We hoped he would be tried and have to pay" for what he did, says the student, who aims to be a teacher one day.

World leaders "have made statement after statement, but in the end they have been weak."