GENEVA (Reuters) -World Health Organization officials said that it had received reports of a mass casualty incident on Tuesday that affected people waiting for food supplies, saying that initial reports point to at least 20 fatalities.

Balah in central Gaza on Monday, sparking a fire. No casualties were reported, as residents evacuated after receiving a warning ahead of the attack. (AP Video: Mohammad Jahjouh, production: Wafaa Shur

At least 45 Palestinians were killed in the Gaza Strip while waiting for U.N. and commercial trucks to enter the territory with desperately needed food, according to Gaza's Health Ministry and a local hospital.

Palestinians in the Gaza Strip are struggling to celebrate one of the most important Islamic holidays. To mark Eid al-Adha — Arabic for the Festival of Sacrifice — Muslims traditionally slaughter a sheep or cow and give away part of the meat to the poor as an act of charity. Then they have a big family meal with sweets.