It's reported that four of the kidnapped Nigerian girls being held by Boko Haram militants have escaped.

A local education officia in Borno state, the area where the girls were abducted from, has revealed they managed to get free, but declined to give further details.

It leaves 219 still missing, according to official figures.

Yesterday, the Nigerian military said they knew where the girls kidnapped by Boko Haram are - but they will not attempt a rescue.

It was reported that a deal to exchange 50 girls for 100 Boko Haram prisoners fell through.

Nigeria's government is under pressure to do more to tackle the group and bring about the girls' release.

Demonstrations have taken place across the country, with many people adamant the government can do more.

The girls were abducted by Boko Haram gunmen from their school in northern Nigeria in April.