Israel's prime minister said Thursday that his country's contestant in the Eurovision Song Contest had "already won" after enduring protests in host country Sweden he called a "horrible wave of anti-Semitism".

In a video message addressed to Eden Golan, who on Thursday was taking part in the second semi-final ahead of the finale in Malmo on Saturday, Benjamin Netanyahu wished her "good luck".

"You know what? You have already won," he said.

"Not only are you proudly and impressively participating in Eurovision, but you are successfully confronting a horrible wave of anti-Semitism," he added.

His comments came after thousands of demonstrators marched through the streets of Malmo to protest Israel's participation in the glitzy song contest, voicing outrage at its war in Gaza.

Gaza's deadliest war erupted after Hamas militants carried out an unprecedented attack on October 7, killing more than 1,170 people, mostly civilians, according to an AFP tally of Israeli official figures.

Israel's retaliatory offensive has killed more than 34,900 people in Gaza, mostly women and children, according to the Hamas-run territory's health ministry.

Militants also took about 250 hostages. Israel estimates 128 of them remain in Gaza, including 36 officials say are dead.

"Hurricane", the Israeli entry sung by Golan, has been partially re-written and given a new title after Eurovision organisers deemed the original too political.

Eurovision rules ban political content.

Since the beginning of the year, several petitions have demanded Israel's exclusion from the 68th edition of the annual music competition.

At the end of March, contestants from nine countries, including Swiss favourite Nemo, called for a lasting ceasefire.