Three weeks after 257 girls were snatched from their school in Chibok, a fortnight after #BringBackOurGirls first appeared on Twitter, and a day after Barack Obama described the kidnapping as both heart-breaking and outrageous, the eyes of the world are finally and firmly fixed on events in the remote reaches of north-eastern Nigeria.

Michelle Obama has become the latest high profile name to tweet her support and in cities as far apart as Abuja, Washington, Los Angeles, Dublin and London, demonstrators have put on red T-shirts to draw attention to the girls’ plight, demand their release, and to vent a deepening sense of anger.

Further protests are due to be held over the next few days in countries including the UK, the US, South Africa, Jamaica and Switzerland.

Further protests are due to be held over the next few days in countries including the UK, the US, South Africa, Jamaica and Switzerland.

The hashtag, which started trending in Nigeria two weeks ago, has now been tweeted more than one million times. It was first used on 23 April at the opening ceremony for a Unesco event honouring the Nigerian city of Port Harcourt as the 2014 World Book Capital City. A Nigerian lawyer in Abuja, Ibrahim M Abdullahi, tweeted the call in a speech by Dr Oby Ezekwesili, vice-president of the World Bank for Africa to “Bring Back the Girls!”

The campaign has reignited the debate over the value of online campaigning or “slacktivism” as it is called by its critics. The hashtag has been used by different organisations to expose the story further online. Amnesty International and Unicef have backed the campaign, as have politicians and celebrities, including Michelle Obama, Hillary Clinton, Wyclef Jean and Chris Brown. Actors Sean Penn, Ashton Kutcher, Justin Timberlake and Bradley Cooper have thrown their weight behind a parallel hashtag: #RealMenDontBuyGirls.

The US first lady said on Twitter: “ur prayers are with the missing Nigerian girls and their families.” She packaged her tweet with a photo of herself in the White House holding a white piece of paper with the message “#BringBackOurGirls” written in black, capital letters.

The Nigerian author Chibundu Onuzo, writing for the Guardian, said: “We have discovered the power of the hashtag over the last week. The simple, emphatic demand #BringBackOurGirls has moved across the Twitter timelines of the famous and the unknown, uniting Nigerian housewives and the US secretary of state, Hillary Clinton.”

On Tuesday, 100 red-clad men and women gathered outside the Nigerian defence headquarters in Abuja to beg the authorities to find the girls amid claims they were to be sold into slavery, a protest that continued into Wednesday.

The chief of the Chibok community in the capital, Hosea Sambido, said the uncertainty had left mothers in his home town unable to eat and had forced fathers into the bush in desperate searches for their daughters.

“Please, we are begging the federal government of Nigeria, please, we are begging our army, which we depend on, please intervene into this matter for us, intervene into this matter for us,” said Sambido.

“Our community is relatively small. If a generation of the same age – 276 – are out, in the future where are we? Who cares? Can our girls go to school now? Help us. Please. Please.”

In Washington, about 75 protesters wearing “Bring Back Our Girls” T-shirts rallied outside the shuttered Nigerian embassy this week to accuse the Nigerian government of failing to protect its young females.

“We are tired of the government putting its head in the sand,” said Omolola Adele Oso, a 35-year-old Nigerian immigrant from Bowie, Maryland. “These girls could be beaten and burned into subservience. The government wants this problem to disappear, but it will not disappear.”

Most – but not all – of the demonstrators were Nigerian immigrants. Amy Thomson, 43, of Chevy Chase, Maryland said she had come to the rally “because I’m a mother and I would feel the same if my daughter were in danger.” Thomson was accompanied by her 11-year-old daughter Emma, who said she had been inspired by the efforts of Malala Yousafzai, the teenage activist from Pakistan who was shot and nearly killed by the Taliban for promoting girls’ education.

“Boko Haram said Allah told them to take the girls,” said Emma. “But I read about Malala, and she said that is not her Allah.”

•Text courtesy The Guardian of London.

Update news