Mozambique will on Wednesday put on trial 180 national and foreign citizens accused of involvement in deadly Islamist attacks in the northern province of Cabo Delgado, sources told AFP.Over the last year, more than 50 people have been killed in gun, grenade and knife assaults in the growing jihadist insurgency, with the militants reportedly seeking to impose Sharia law in the Muslim-majority province.The trial - the first since the attacks began - will be held in an improvised court in the jail where hundreds of suspected militants are being detained in Pemba, the provincial capital of Cabo Delgado, a court source said on Tuesday.Among the defendants are 5O citizens from neighbouring Tanzania."This is only the first group to be tried among hundreds of detainees," a police source said.The attackers are believed to have staged their first attack on a police station and military outpost in the town of Mocimboa da Praia in October 2017. Two officers died and 14 attackers were killed.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and FacebookAs the attacks spread through the province, several hundred Muslims were arrested, some of them Tanzanians, and several mosques were forced to close.In the latest major attack, 12 villagers were killed and 14 wounded two weeks ago.Back in June, while visiting one of the areas worst hit by the attacks, President Filipe Nyusi vowed the security forces would be "firm and ruthless" in pursuing the jihadists."The defendants are not accused of being terrorists since at the time of the attacks, there was still no law against terrorism in Mozambique," a public prosecutor said.An anti-terrorism law was passed in April this year. Anyone detained after the new law will be tried under the legislation, which allows for heavier sentences.Locals and authorities call the assailants Al-Shabaab, although the group has no known link to the Somali Islamists of that name, nor has it issued any claim of responsibility or demands.The attacks have shaken plans to exploit vast natural gas discovered off the shores of Cabo Delgado.