Twitter users have launched a campaign to mobilise help for the millions of people suffering due to a devastating famine in Somalia.

Without an immediate injection of funds, the UN warns that "people will simply starve to death" in the struggling Horn of Africa country.

"Livelihoods, futures and hope will be lost" unless action is taken immediately, UN under-secretary general for humanitarian affairs Stephen O'Brien told the Security Council last week.

The warnings prompted the hashtag #TurkishAirlinesHelpSomalia to trend worldwide on Wednesday night, attracting support from celebrities including Ben Stiller.

The call was started by French entrepreneur and social media star Jerome Jarre, who posted a video on Twitter talking about a six-year-old girl who died of dehydration after walking over 140 kilometres with her mother in search of water.

In the video, Jarre accuses mainstream media outlets of failing to properly cover the crisis, giving the impression that nothing can be done to aid people at risk of starvation.

Jarre calls this limited coverage “un-empowering,” going on to say: “The reality is, we can come together, we can look for solutions, and we can try. Especially with social media.”

🚨MAINSTREAM MEDIA WON'T TALK ABOUT IT !!!



REVOLTING !!!



LET'S MAKE NOISE !!!#TurkishAirlinesHelpSomalia 🚨 pic.twitter.com/iiyQrzyLC9 — JÉRÔME JARRE (@jeromejarre) March 15, 2017

The hashtag was a call to Turkish Airlines, believed to be the only commercial airline that currently flies to Somalia, to transport aid to the country.

Jarre called on social media users to bring the problem to the attention of water and food companies as well as Turkish Airways, in the hope that the media attention the hashtag attracts will induce action.

Over 50 percent of Somalia's population - around 6.2 million people - are in need of urgent humanitarian assistance, according to the UN, and around a million children under the age of five will be acutely malnourished this year.

“What I saw and heard during my visit to Somalia was distressing - women and children walk for weeks in search of food and water," O'Brien said.

"They have lost their livestock, water sources have dried up and they have nothing left to survive on,” he went on, saying that “with everything lost, women, boys, girls and men now move to urban centres.”

The hashtag attracted support from celebgrities across the world, including American football star Colin Kaepernick.

Ben Stiller also shared a video urging support for the online campaign.

If you have 2 minutes and 20 seconds check this out. #TurkishAirlinesHelpSomalia pic.twitter.com/r0u3xh5spG — Ben Stiller (@RedHourBen) March 15, 2017

Others who joined in the campaign included Mexican YouTube personality Juanpa Zurita, Desperate Housewives star Charlie Carver, Argentinian actor Ignacio Serricchio and US actor and comedian Gabriel Conte.

Turkish Airlines has responded to the campaign, saying it had "got the call".

Turkish Airlines had already been planning to send cargo planes filled with aid to Somalia, Yemen and South Sudan, according to Kerem Kinik, head of the Turkish Red Crescent aid organisation.