Sitting in her modest apartment near Amsterdam, Wafa turns on her phone and opens WhatsApp. She’s filled with a mixture of hope and fear.

Covering her face with her hijab, Wafa, 40, weeps as she waits for two blue check marks confirming Maha has received her message — the only sign that her 23-year-old daughter is still alive, reports the CNN.

Maha and her nearly 2-year-old son Odai are trapped in Raqqa, ISIS’ de facto capital in Syria and one of the most isolated places on Earth. When she can find a rare internet connection away from watchful eyes, Maha talks to her mother via WhatsApp voice message.

“When I don’t hear anything, when there is no news, it’s like something inside me is dying,” Wafa says.

When Wafa arrived in the Netherlands after fleeing Raqqa in 2014, she pleaded with her daughter to follow. Instead, Maha stayed behind with her husband and son, promising to join her mother later. But she wouldn’t get the chance. ISIS’ religious police beheaded Maha’s husband after finding a message to a Syrian regime soldier on his phone.

Now, as US-led coalition forces encircle the ISIS stronghold, an escape seems even more hazardous and Maha’s voice messages to her mother have become increasingly desperate. With so much emotion in their voices some sections are inaudible.

The following conversation has been adapted from voice messages exchanged between Maha and Wafa on WhatsApp since January. Wafa shared these messages with CNN.

On January 4, Maha wrote: Mom, Odai got infected from drinking poisoned water, we managed to get to the emergency room here, the doctor told me it is extremely important for him to drink clean water but it is hard to find it here. Mom, I'm desperate, I don't know what to do. I swear, I don't know.

Wafa, the mother replied: Sweetie, try to find him clean water and give it to him. Sweetie, let me know how you're doing. Sufficient for us is God and he is the best disposer of affairs [an Islamic expression meaning God is in control].

The last message came from Maha on 18 June: My son is dehydrated, this water is causing him diarrhea. There is no nutrition, try, my son is dying in front of my eyes. Try, my faith is in you, try. Please try. (Inaudible) You know what I am doing is a big risk, but I took the risk and sent it.

The mother sent a reply on 20 June: I curse on them sweetie, they live like princes, they can afford anything. We’re the only ones who are suffering. We are shattered. We are dead.

Maha is still sending her mother voice messages from Raqqa when she can.

The names of the people featured in this report have been changed to protect their identities.