During the British Mandate, tension between the Jewish and Arab population increased. A wave of Arab attacks during 1920 and 1921 caused many Jewish residents to flee and resettle in Tel Aviv, initially a marginal Jewish neighborhood north of Jaffa. The Jaffa riots in 1921, (known in Hebrew as "Meoraot Tarpa") began with a May Day parade that turned violent. Arab rioters attacked Jewish residents and buildings killing 47 Jews and wounding 146. The Hebrew author Yosef Haim Brenner was killed in the riots. At the end of 1922, Tel Aviv had 15,000 residents: by 1927, the population had risen to 38,000.