The bloody crackdown on Shiite protesters this week in Nigeria has highlighted the oppression of a religious minority that experts say is driven by a Sunni Muslim elite backed by Saudi Arabia."Being a Shiite under this current Buhari administration is... being persecuted," said Islamic Movement of Nigeria (IMN) spokesperson Ibrahim Musa to AFP."We have suffered more discrimination under this administration than with any other in the past," said Musa. "We are not allowed to worship our god according to our convictions."On three separate occasions in less than a week, the Nigerian military and police shot live bullets on Shiites marching near and in the capital city of Abuja to celebrate a religious holiday and demand the release of their imprisoned leader.The death toll depends on the source: while the military says that six people died, the IMN says 49, a figure backed up by Amnesty International, which said on Wednesday that at least 45 people were killed in an "unconscionable use of deadly force by soldiers and police."The US embassy in Nigeria said it was "concerned" about the deaths and called for a "thorough investigation of the events". But to justify opening fire on the Shiite group, the Nigerian army on Friday posted a video of US President Donald Trump saying soldiers would shoot Central American migrants throwing stones."Not only did they use stones but they were carrying petrol bombs, machetes and knives, so yes, we consider them as being armed," said Nigeria's defence spokesperson John Agim. Riyadh and Tehran This violence has happened before. It reignited the tumult of December 2015 when an army crackdown in Zaria, IMN's stronghold in Nigeria's north, killed 300 supporters, according to rights groups.Leader Ibrahim Zakzaky, who was arrested and imprisoned after the clashes, lost an eye and several family members in the violence.Zakzaky has been challenging Abuja's authorities for years with his goal of establishing a Shiite Islamic regime in Nigeria, Africa's largest economy. In late 2016, a court ruled that his continued detention without charge was illegal and ordered his release yet the decision was never executed.Since then, Zakzaky has been charged with culpable homicide in connection with the Zaria clashes.The IMN, which emerged as a student movement in the late 70's, is still close to Tehran today. Inspired by the Islamic revolution in Iran, the sect is met with hostility in Nigeria, where the Sunni elite are allied with Saudi Arabia. President Muhammadu Buhari and Atiku Abubakar, the leader of the opposition contesting the 2019 presidential polls, are Sunni and have both said nothing about the violence this week."There is this belief that Shiites are not proper Muslims," said Nigerian political analyst Chris Ngwodo."This fundamental disagreement over ideology could explain the ferocity used by the security forces against the protestors."Radicalisation threat In Nigeria's predominantly Muslim north, the IMN is vastly outnumbered by the Salafist movement Izala, which was founded around the same time as the IMN.Izala is close to both Riyadh and Abuja and its satellite television channel Manara often broadcasts anti-Shiite rhetoric.Its members have also clashed with IMN supporters several times during Shiite processions.Izala is funded by Saudi Arabia, which has enabled the construction of mosques and schools across the country."A number of people in the (federal) government are Izala members and have close ties to Saudi Arabia," said a source speaking to AFP on condition of anonymity."Some within the establishment are using the government resources for a religious battle, against what they consider as apostasy."The worst case scenario would see the Shiites become radicalised in the face of oppression, an outcome that would replicate the trajectory of Boko Haram jihadists in the northeast who took up arms against the government in 2009."Zakzaky is a very charismatic leader, the movement was kept alive despite his detention and his supporters are ready to die for him," said Cheta Nwanze, research head at SBM Intelligence in Lagos."The repression can only contribute to radicalise them."Zakzaky, who is weak following the attack according to his lawyer, is being held in a secret location and is due to appear in court on November 7.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.