LONDON: Two years ago the world was in uproar over the abduction of more than 200 schoolgirls by the Islamist militant group Boko Haram from a secondary school in Chibok in northeastern Nigeria.

Under the hashtag #bringbackourgirls, politicians, celebrities and the public globally united to demand the return of the girls who disappeared without a trace.

Two years later, and after several false leads, the girls are still missing.

Here are five key facts about the Chibok schoolgirls:

1. On April 14, 2014, Boko Haram militants kidnapped 276 school girls, mostly aged between 16 and 18, from a secondary school in Chibok in Borno State, northeast Nigeria. About 50 of the girls escaped but 219 were captured.

2. Nigeria's government and military faced heavy criticism for their handling of the incident, with towns and cities across the nation witnessing protests. President Goodluck Jonathan, who declined to comment on the kidnappings for almost three weeks, was criticised, and became the first sitting Nigerian president to lose an election, in 2015.

3. The kidnappings prompted a strong social media reaction, with the phrase #bringbackourgirls tweeted around 3.3 million times by mid-May 2014. U.S. first lady Michelle Obama joined the campaign, as did Malala Yousafzai, the Pakistani schoolgirl shot by the Taliban after campaigning for girls' education.

4. Hope for the girls was briefly raised in April, 2015, when the Nigerian military announced it had rescued 200 girls and 93 women from the Sambisa forest. It was later revealed that the Chibok girls were not among them.

5. About 2,000 girls and boys have been kidnapped by Boko Haram since the beginning of 2014, according to Amnesty International, which says they are used as cooks, sex slaves, fighters and even suicide bombers.