Why is tweeting #FreePalestine such a political bomb for celebrities like Rihanna?

As the conflict in Gaza rages on, many people around the world are taking to social media to express their views on the decades long situation in the Middle East.

Pop star Rihanna tweeted in support of Palestine using the #FreePalestine tag before deleting it several minutes later. (AAP)

Among them, are some big celebrities.

One of the hashtags that's been not only the most used, but perhaps also more controversial, is the '#FreePalestine' hashtag which people are using to show their sympathies in the favour of the Palestinians.

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

Pop star Rihanna tweeted in support of Palestine using the #FreePalestine tag before deleting it several minutes later.

Popstar Rihanna also tweeted the hashtag, only to delete it several few minutes later after receiving a barrage of abusive messages.

Antony Lowenstein is an independent journalist and author and also a prolific tweeter.

He spoke to Santilla Chingaipe about what the hashtag means.