text: Security forces are still searching for the missing students, who were abducted by Boko Haram Islamist militants on 14 April.
  The military fuelled confusion in the immediate aftermath by incorrectly saying most of the girls had been rescued.
  Parents and some girls who escaped say more than 200 students were seized from their school in Chibok in north-eastern Borno state by gunmen overnight. A local government official confirms the incident, saying the exact number of missing students is unclear but puts the number at around 100.
  Nigeria's military says most of the girls managed to escape or were freed and releases a statement saying only eight girls are still missing.
  Locals say many remain unaccounted for and parents of the missing girls head into the Sambisa forest near the Cameroonian border to search for them. On their return they say they did not see any Nigerian soldiers in the forest.
  Major General Chris Olukolade, a military spokesman, says a report stating that most of the girls had been freed was incorrect but was "not intended to deceive the public." Parents insist that more than 200 girls are still missing. The military has not rescued any of the girls.
  Asabe Kwambura, headmistress of the school in Chibok, appeals to the government to do more to save the girls and calls on the kidnappers - thought to be members of the Boko Haram group - to "have mercy on the students."
  Ms Kwambura tells the BBC that at least 190 girls are still missing, contradicting a local state governor who said that around 80 of the students were yet to be found. Footage emerges of the school shortly after the attack, showing the classrooms after they were set alight by gunmen.
  A government source tries to explain the discrepancy, by telling the BBC it was initially thought only science students had been seized ahead of their exam but there were also 105 art students in the hostels at the time, which the authorities had not realised.
  Nigerians take to social media to show their anger at the government response and Ibrahim M Abdullahi, a lawyer in Abuja, sends the first tweet using the hashtag #BringBackOurGirls.
  Hundreds march through Abuja to protest at government "indifference" to the mass abduction. A community leader from Chibok warns that the girls may have been taken to neighbouring states and forced to marry militants. He says that 230 girls are missing - another increase in the figure.
  Desperate parents in Chibok stage a protest calling on the government to do more in the search for the missing girls. Protests are also staged again in towns and cities across Nigeria.
  Nigerian police say militants are holding 223 girls, after 53 of the initial 276 girls who were abducted managed to escape. He explained the higher figure by saying pupils from surrounding schools had gone to Chibok to take exams, as it was believed to be safe.
  President Goodluck Jonathan make his first public comments since the abduction, saying his government is seeking assistance from the US and other world powers to tackle Nigeria's "security challenge".
  In a video statement, Boko Haram leader Abubakar Shekau says his group were behind the abduction of the girls and threatens to "sell" them in the market as "slaves". The US says it has information that the girls may have been moved into neighbouring countries but Chad and Cameroon deny the girls are being held on their soil.
  Barack Obama says the "heartbreaking" abduction" may be the event that helps to mobilise the entire international community" to finally act against Boko Haram. He says US experts are being dispatched to help find the girls. Eleven more girls are abducted by gunmen from nearby areas of Borno state.
  The #BringBackOurGirls hashtag hits 1 million tweets and US First Lady Michelle Obama joins the online campaign, posting a picture of herself on photo-sharing site Instagram holding a piece of paper with the hashtag on. Nigerian police offer 50 million naira (Â£180,000; $300,000) for information that could help track the girls down.
  Malala Yousafzai, the Pakistani schoolgirl who survived a shooting by Taliban insurgents, joins the #BringBackOurGirls campaign and says the world must not stay silent over the abduction.
  Experts from the US and UK arrive in Nigeria to help with the search for the missing girls.
  Amnesty International accuses Nigeria's military of ignoring warnings before the abduction. The human rights group said credible sources told it that the army were notified of an impending attack four hours before it happened but did nothing. The government says it doubts the report but will investigate.
  The governor of Nigeria's Borno state says he has information on the whereabouts of the girls and has passed reports of possible sightings to the military. He says he does not think they have been taken across the border to Chad or Cameroon.
  Boko Haram release a new video claiming to show around 130 of the abducted girls at an unknown location. In the video, the group's leader says he will not free the girls until authorities release all imprisoned militants. He also says the girls have converted to Islam.
target: Nigeria's government has been accused of being too slow in its response to the kidnapping of more than 200 girls from a school in the north of the country.