Pop idols and professional athletes are going public with strong views about Gaza, putting their relations with fans on the line while stirring up a social media frenzy.

More often than not, celebrity sympathies have been leaning in favor of the Palestinians as the Israeli assault on Gaza rolls into its fourth week and the death toll keeps rising.

Zayn Malik of the British boy band One Direction was the latest to voice his concern when he posted "#FreePalestine" on his Twitter account on Sunday.

As of Tuesday, his message had been retweeted 220,000 times, and favorited just as often, among his 13 million followers worldwide.

But it also angered Israeli fans - with some going so far as to make death threats against the 21-year-old heartthrob, a British-born Muslim of Pakistani heritage.

"People who don't live in Israel don't have any right to say their opinion out loud," tweeted one young woman, Shaked Erez, who added the hashtag #freeisrael for good measure.

The roster of celebrities - many not known for political activism - weighing in on Gaza has grown since pop diva Rihanna and basketball star Dwight Howard tweeted #FreePalestine.

Social media gives celebrities unprecedented power to engage directly with millions of fans worldwide, said George Washington University media professor William Youmans.

"But when they wade into political matters, they run the risk of alienating a certain number of their fans," Youmans, who's been monitoring celebrity Gaza tweets, said on Tuesday.

Rihanna - who performed in Tel Aviv last year - deleted her post within minutes, as did Howard who declared that he'd made a mistake and that he would never comment again on global affairs.

Dance-pop songstress Selena Gomez meanwhile caused a stir with an image on her Instagram account that began: "It's About Humanity. Pray for Gaza."

Israel is not without its defenders - none fiercer than indefatigable comedienne Joan Rivers.

"Let me tell you, if New Jersey were firing rockets into New York, we would wipe them out," said Rivers, 81.

(China Daily 07/31/2014 page11)