Nigerien authorities have evacuated thousands of people from Lake Chad in southeastern Niger over fears of possible attacks by Boko Haram militant group.Last week, local authorities urged Lake Chad residents to evacuate their islands by Monday, citing security fears.The move came a week after Boko Haram militants attacked Karamga island in Lake Chad on border with Nigeria, leaving at least 74 people dead."The call [for residents to leave] has prompted thousands of people to leave the area in very difficult conditions," Moussa Tchangari, secretary-general of "Space is Alternative Home" NGO, told the Anadolu Agency.MP Lamido Moumouni also criticized the call for residents to leave, saying the move "facilitates Boko Haram mission to occupy the islands."There was no official comment on the evacuation in Lake Chad, which is home to nearly 60,000 people.In recent months, Nigerien towns on the border with Nigeria have been rocked by multiple attacks by the Boko Haram militant group.Nigeria and its neighbors-including Niger, Cameroon and Chad-have recently launched a joint counterterrorism campaign endorsed by the African Union and other regional bodies.