Boko Haram is fracturing as shortages of weapons and fuel foment tensions between its foot soldiers and leaders, women rescued from Islamist jihadi fighters by Nigerian troops said on Monday (4 May).

The group abducted an estimated 2,000 women and girls last year as it sought to carve out an Islamic state in the northeast of Africa's biggest economy. The army has freed nearly 700 in the past week as it advances on Boko Haram's last stronghold in the vast Sambisa forest.

The militants began complaining to their captives about lacking guns and ammunition last month, two of the women said, and many were reduced to carrying sticks while some of their vehicles were either broken down or lacked fuel.

"They were always complaining that their leader, I can't recall his name now, but that their leader has deceived them in fighting and killing in the name of religion. And now the unfaithful were killing them. They don't give them guns and nothing good was happening to them. As such they were not happy with their leaders. We hear them complain everyday," said rescued woman Hanatu Musa.

Even the wife of their captors' leader, Adam Bitri, openly criticised him and subsequently fled, two of the women said, with one describing Bitri as short and fat with a beard.

Of 275 freed captives brought to a government-run camp for internally displaced people, only 61 were over 18, and many small children hobbled around visibly malnourished.

Binta Ibrahim said the women were forced to marry Boko Haram fighters. Those who refused were sold as slaves.

"They started taking money from people, selling us off, some would also serve as house helpers for their wives, most of the buyers were the Boko Haram fighters themselves," Binta said.

The women said they were kept inside, occasionally brought food and sometimes beaten severely. The children were left to run around or do errands for Boko Haram while those who were fighters were trained to shoot guns.