Some Girls Escaped Just After Boko Haram Attack

It has now emerged that the girls' parents did not inform authorities at Chibok Girls Secondary school, and their situation only became clear following a more accurate compilation of all those missing.

The four are believed to be among the 50 or so students who escaped through the bush shortly after being abducted on April 14.

Borno Education Commissioner Musa Inuwa Kubo only made the announcement on Wednesday, although he informed the Presidential Fact-Finding committee of the news when he made a presentation last week in the Borno State capital, Maiduguri.

He said the news means there are a total of 219 girls still missing.

Sources close to the investigation told Sky News a few days ago that a Government deal to free some of the girls in exchange for the release of Boko Haram prisoners had collapsed.

The deal foundered after the Nigerian President travelled to the anti-terror summit in Paris, hosted by French leader Francois Hollande.

It is believed there was vehement opposition to the deal, with the British in particular strongly warning against it.

Since then, former president of Nigeria Olusegun Obasanjo has taken up the mantle of trying to negotiate with the militants in an attempt to free the girls.

He is in support of a prisoner-for-hostage swap deal. However, he has a difficult relationship with the current presidency and does not have the authority to negotiate any deal on the Government's behalf.

A source close to the former president told Sky News: "Obesanjo is worried that Nigeria's prestige in Africa  as a major continental power has been diminished by President Goodluck Jonathan's decision to bring in Western military help, including from the Untied States."

Nigeria's army chief said earlier this week that the military knew where the girls, but he also appeared to rule out using force to free them.