KHAN SHEIKHOUN (NYTIMES) - Aya and Ahmed, nine-month-old twins, were among the 86 people killed in Tuesday's (April 4) gas attack in Khan Sheikhoun, Syria. Their father Abdel Hameed Alyousef asked a photographer to take pictures as he held their bodies.

He turned the babies' faces toward the camera and said, "tell them, 'goodbye dad'." In an interview with a local activist, Mr Alyousef described the start of the air strikes at 7am.

"I took my wife and children and left the house," he said, through choking sobs. "As we were leaving, just about five minutes later, we started to smell nasty smells." He said his children began to cough and he handed them to their mother and told her to flee the town.

He went to check on his brothers and their children. They were struggling to breathe. He saw people fall in the street and begin foaming at the mouth before losing consciousness himself.

Later, he found out his wife and babies had died. And he buried them.

He walked through the graves, calling out the names of other family members who were also killed and buried in the graveyard, pausing at each, and sobbing.

After the burial, "I saw Ahmed and Aya, and carried them close to my heart", Alyousef said in the interview. "We buried them, I took Ahmed and Aya and buried them. I buried my own children." He said he had lost at least 25 members of his extended family in the attack.