A court in Niger has sentenced 17 members of the violent Islamist movement Boko Haram to between two and seven years in jail, a senior state prosecutor said on Monday."Of 42 suspects on trial, 17 got between two and seven years in prison and 21 others were released" at the end of a six-day trial in the southeastern Diffa region, Chaibou Samna, prosecutor at the high court in Niamey, told AFP.The trial of the four other suspected members of the jihadist movement, which originated in Nigeria and has launched bloody attacks in neighbouring countries, was postponed until mid-October, Samna said.The men held for trial included Niger nationals and Malians as well as Nigerians, accused of "criminal association connected with a terrorist enterprise", another judicial source said.Some were "captured during fighting" or during security checks carried out under a state of emergency imposed on the Diffa region, across the border from Nigeria, according to a source in the security forces.The first trials of Boko Haram suspects in Niger were held in the capital Niamey in March 2017. Some were convicted and jailed for up to nine years, while others were acquitted for lack of evidence.The trials were moved this year to Diffa, which has endured many Boko Haram attacks since February 2015. Arrested men were transferred in from Niamey and the two southwestern towns of Kollo and Koutoukale. Boko Haram has no rear bases in Diffa, but youths from the territory were lured to join the jihadists from 2015, when the movement offered them up to $540 per month. Since December 2016, 200 Niger nationals have left Boko Haram and turned themselves into authorities in Diffa. They are interned in a camp where they undergo rehabilitation before being allowed to return to their families under an amnesty.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.