A United Nations convoy carrying workers for a polio vaccination in Gaza was held at gunpoint at an “Israeli” military checkpoint, a UN spokesperson said Tuesday.

Stephane Dujarric, spokesperson for UN Secretary-General Antonio Guterres, added that shots were fired and its vehicles were rammed by a bulldozer.

He called the incident the “latest example of the unacceptable dangers and impediment that humanitarian personnel in Gaza are experiencing by Israeli forces.”