One more of the female students abducted by militants from a secondary school in north-east Nigeria a decade ago has been rescued, the army says.

The army said on Thursday that it had rescued the young woman, who is five months pregnant, along with her three children.

The abduction of the 276 girls from their school in north-eastern Nigeria in 2014 by Boko Haram militants shocked the world and sparked a global campaign to #BringBackOurGirls, which included former US First Lady Michelle Obama.

More than 180 girls have either since escaped or been freed from Boko Haram hideouts in Sambisa forest in north-eastern Borno state.

Some of the freed and rescued girls have returned home pregnant or with children.

About 90 others are still missing and are suspected to still be held by the militants.