Drawn from the biblical Book of Esther's account of how the Jews were spared genocide in ancient Persia, Purim is commemorated with the wearing of all kinds of fancy dress costumes, donating food for feasts - and drinking to excess.
But this year, Israel, which began emerging from its third national lockdown on Feb. 21, reimposed night curfews for the long Purim weekend and limited access to Jerusalem.
Purim parties were banned, with fines for anyone hosting them.
That led to spontaneous street parties in Tel Aviv.
Police commander Ziv Saguy said they were giving out 200 fines an hour.
Long traffic jams formed on the road to Jerusalem as police tried to stop large groups of reaching the holy city for the festival. Some people ditched their vehicles and walked up the highway instead.
Some ultra-Orthodox have also defied state-ordered closures of schools and synagogues, touching off clashes with police.