One day in July, Rafiq slipped out of the world¡¯s largest refugee settlement, in southern Bangladesh, and crossed the border into Myanmar on a small boat. His destination: a ruinous civil war in a nation that he had fled in 2017.

Thousands of Rohingya insurgents, like 32-year-old Rafiq, have emerged from camps housing over a million refugees in Cox¡¯s Bazar, where militant recruitment and violence have surged this year, according to four people familiar with the conflict and two internal aid agency reports seen by Reuters.

¡°We need to fight to take back our lands,¡± said Rafiq, a lean and bearded man in a Muslim prayer cap who spent weeks fighting in Myanmar before returning after he was shot in the leg.