A call for attention to be turned towards the crisis in Syria has rippled through social media, with some people turning their Facebook profile pictures yellow to draw attention to the chemical attack on civilians by the government.
At least 70 people were killed in the worst chemical attack in rebel-held Syria after a nerve gas believed to be sarin was dropped by Syrian aircraft on the town of Khan Sheikhoun on Tuesday (April 4). The government has denied the attack.
Harrowing images and videos show civilians convulsing from the effects of the nerve gas.
On Facebook and Twitter, a call for users to change profile pictures to a plain yellow colour, symbolising toxic gas, has been answered by many.
Syrian journalist Rami Jarrah on Tuesday called on Facebook users to raise awareness of the situation, where "attacks continue this moment on both medical and civil defence facilities responding to the attacks".
Artwork has been shared as well, including an image of dead children hung in the sky by toxic balloons around their necks.
Caricatures and cartoons, several of them old ones created in response to previous chemical attacks in Syria, also made their rounds on social media.
On Twitter, the hashtag #SyriaGasAttack has proliferated with tweets expressing condolences for the dead and calls for action.
Jacqual Johnson wrote: "I will never be able to remove from my mind the images and sounds of CHILDREN gasping for air. My heart is heavy."
Some have called on US President Donald Trump to help Syria.
Twitter user Sara appealed to Mr Trump to "please help the citizens of #Syria we can't stand by while little children are decimated with toxic chemicals".
Mr Trump on Wednesday (April 5) said the attacks were "unacceptable" and that he has changed his attitude towards Syria and Syrian President Bashar al-Assad.
Western countries, including the United States, blamed Mr Assad's armed forces for the attack.
Russia, which has been helping Mr Assad in fighting rebels seeking to overthrow him, said the poison gas had leaked from a rebel chemical weapons depot struck by Syrian bombs.