United Nations human rights chief Volker Turk warned Wednesday there was a heightened risk of atrocity crimes in Gaza, urging parties involved to refrain from committing such violations.

"My humanitarian colleagues have described the situation as apocalyptic. In these circumstances, there is a heightened risk of atrocity crimes," Turk told reporters in Geneva.

"Measures need to be taken urgently, both by the parties concerned and by all states, particularly those with influence, to prevent any such crimes."