Hundreds of captives freed from Boko Haram mountain hideout

At least 360 people kidnapped by Boko Haram jihadists from a mainly Muslim community in Nigeria's north-eastern Borno state in March have been freed from a remote mountain hideout.

The circumstances of how they were freed are disputed. The army says it had launched an unprecedented intelligence-led operation that had been weeks in the planning and taken the Islamist militants by surprise.

But a local group, the Borno South Youth Initiative, says it mediated the unconditional release, putting the number of those freed at 416.

Mass abductions by groups for ransom have become a common tactic in Nigeria. Boko Haram gained notoriety in 2014 for kidnapping more than 200 schoolgirls from Chibok.

That spawned a range of groups that use kidnapping to raise funds, focusing on soft targets such as schools, churches, mosques and remote villages.

It is illegal to pay ransoms in Nigeria, but analysts say payments by desperate families, intermediaries or, in some cases, state authorities have fuelled the abductions.

Military spokesperson Lt-Col Haruna M Sani described the assault on Boko Haram's Mandara mountain hideout, "under cover of darkness", as one of the military's "most significant hostage rescue operations" in the north-east.

"Faced with the speed, precision, and overwhelming combat power of the advancing troops, several insurgents abandoned their positions and fled into surrounding mountainous terrain , while others surrendered," he said in a statement.