- A smaller demonstration in support of Israel has also taken place.
- Climate activist Greta Thunberg, was among those attending the pro-Palestinian protest.
Thousands of pro-Palestinian demonstrators have gathered in the Swedish city of Malmo to protest against Israel's participation in the Eurovision song contest.
It comes as the city prepares to host the competition's second semi-final on Thursday night, in which Israel's entrant Eden Golan is performing.
On Wednesday, Ms Golan was booed during a rehearsal of her song Hurricane.
A smaller demonstration in support of Israel has also taken place.
Climate activist Greta Thunberg, was among those attending the pro-Palestinian protest.
She told the BBC that there was a "moral obligation to act" and to speak out against Israel's military operation in Gaza.
"If we are tens of thousands of people flooding the streets of Malmo when Eurovision is taking place, saying we will not accept this to continue, then it's a very strong signal - and it does make a difference," Ms Thunberg said.
Another protester, Matilda Varatta, told the Reuters news agency that she would like to see Israel disqualified as Russia was in 2022 following its full-scale invasion of Ukraine.
"It's not true that the Eurovision is not political, it has always been political, and it will always be," she said.
Earlier, Ms Golan said that she was "proud to represent my country" and that "nothing will deter" her.
"I'm focused on music, on the good energy, and there are so many people supporting me, and I feel like I have such an honour to represent my country, especially in these times".
At the pro-Israel demonstration, people could be heard singing Hurricane in support of Ms Golan amid a significant police presence.
"I'm not that interested in Eurovision," one demonstrator, Yael Sages Wahlström, told Sweden's Svenska Dagbladet newspaper.
"But since there has been such a huge storm of hate against Israel, I wanted to support".
The Israeli Broadcasting Corporation, which organises the country's contest entry, says it has asked the European Broadcasting Union to prevent a repeat of Wednesday's booing incident.
The Swedish authorities say they have heightened security in place and are prepared for potential unrest.
Israel is currently engaged in a military campaign in Gaza, which they launched as a response to Hamas' cross-border attack on southern Israel on 7 October.
About 1,200 people were killed and 252 others were taken hostage.
More than 34,900 people have been killed in Gaza since then, according to the territory's Hamas-run health ministry.