The head of a UK-based medical charity working in Gaza says the health situation has reached a “catastrophic stage” because of the impossibility of acquiring supplies to treat the hundreds of patients flowing into field clinics.

David Wightwick, CEO of UK-Med, said his team is focusing on the southern city of Khan Younis where the largest proportion of the population is now located. His aid group set up a field hospital in al-Mawasi and has two others in the south.

About 1,400 victims of war violence in the region seek medical help from UK-Med each day, Wightwick told Al Jazeera.  Most of the conflict-related emergencies are blast injuries and gunshot wounds.

But medical supplies have become scarce ever since Israeli forces captured the Rafah border crossing with Egypt in May.