The Jaffa riots refers to the riots and killings that took place in the British Mandate of Palestine between 1 and 7 May 1921.
On the night before 1 May 1921, the Jewish Communist Party (precursor of the Palestine Communist Party) distributed Arabic and Yiddish fliers calling for the toppling of British rule and the establishing a "Soviet Palestine". The party announced its intention to parade from Jaffa to neighbouring Tel Aviv to commemorate May Day. On the morning of the parade, despite a warning to the 60 members present from one of Jaffa's most senior police officers, Toufiq Bey al-Said, who visited the party's headquarters, the march headed from Jaffa to Tel Aviv through the mixed Jewish-Arab border neighbourhood of Menashia.
Another large May Day parade had also been organised for Tel Aviv by the rival socialist Ahdut HaAvoda group, with official authorisation. When the two processions met, a fistfight erupted, and the Palestine police chased the communists back to Jaffa.
Hearing of the fighting and believing that Arabs were being attacked, the Arabs of Jaffa went on the offensive. Dozens of British, Arab, and Jewish witnesses all reported that Arab men bearing clubs, knives, swords, and some pistols broke into Jewish buildings and murdered their inhabitants, while women followed to loot. They attacked Jewish pedestrians and destroyed Jewish homes and stores. They beat and killed Jews in their homes, including children, and in some cases split open the victims' skulls.
As in the previous year's Nebi Musa riots, the mob tore open their victims' quilts and pillows, sending up clouds of feathers. Some Arabs defended Jews and offered them refuge in their homes; many witnesses identified their attackers and murderers as their neighbours. Several witnesses said that Arab policemen had participated.