Cairo ( CNN ) -- Overcrowding inside a cathedral where Coptic Christians had gathered to pay last respects to their pope caused a stampede that left three people dead and more than 50 injured , a health official said . Coptic Pope Shenouda III , who led the Coptic community for more than four decades , died Saturday . He was 88 . On Sunday , thousands of Christians paid their respects to him at the Coptic cathedral in Cairo where his body went on display in an elaborate golden crown and red and golden robes . The mass of people inside the cathedral prompted the stampede , according to Deputy Health Minister Hisham Sheeha , who said three were killed and 52 injured , most suffering from lack of oxygen and low blood pressure . Shenouda 's funeral will be held early this week and is expected to bring millions of Christians onto the streets of Egypt at a time when tensions with the Muslim majority are high . Egypt 's Christian minority has been the target of a number of high-profile attacks in the past several years . The bombing of a major church in Alexandria in January 2011 left at least 21 people dead , and at least 25 Coptic Christians and their supporters were killed in clashes with the army in October . That incident was the bloodiest in Egypt since its revolution in February . Christians are a very small minority in Egypt , although the Coptic Orthodox Church is the largest Christian church in the Middle East , according the Coptic Orthodox Church Centre in Stevenage , England . The U.S. State Department estimates that Egypt is roughly 9 % Coptic Christian , but the Pew Forum on Religion & Public Life , which released a report on the global Christian population last year , says it is probably closer to 5 % . Egypt did not release the number of Christians in its 2006 census , the think tank said . The leader of the Coptic Christian community since 1971 , Shenouda was in poor health off and on for many years . He traveled to the United States to undergo medical tests last year . He died of renal failure `` due to the diabetes he endured for years , '' said Sheif Doss , head of the Egyptian General Coptic Association . The pope had lung cancer , which spread to the rest of his body , Doss said . `` The funeral is expected to take place in two days , as massive preparations must take place first . It is a historical event and 2 million people are expected to attend the prayers . I do n't expect violence though , '' Doss said . Egypt 's Supreme Council announced Sunday three days of mourning for the Coptic Christian community . Shenouda will be buried Tuesday at Emba Bishoy monastery in Wadi Natroun , northwest of Egypt 's capital , said Markus Askuf , spokesman for the Coptic Church . The area is home to some of the world 's earliest Christian monasteries . Shenouda , a journalist in his youth , was once sentenced to spend four years in Wadi Natroun by the late president Anwar Al-Sadat . In addition to millions of followers in Egypt , the Coptic church has adherents in Europe , Canada , the United States , Kenya , Zimbabwe , Namibia and South Africa . U.S. President Barack Obama and his wife offered their condolences Saturday after news of Shenouda 's death spread , saying he will be remembered as `` a man of deep faith , a leader of a great faith , and an advocate for unity and reconciliation . '' `` His commitment to Egypt 's national unity is also a testament to what can be accomplished when people of all religions and creeds work together , '' the Obamas said . When a Coptic pope dies , all 150 bishops of the church 's Holy Council appoint an acting patriarch until a vote is conducted for a successor , Doss said . Thousands of bishops , priests and monks are eligible to vote . The most senior bishop usually takes the role of acting patriarch . In this case , that would be Bishop Michael of Asiut . If he declines , Bishop Bakhamious of Behira is next in line , Doss said .
NEW : Stampede breaks out inside cathedral , leaving 3 dead and 52 injured . The funeral could bring millions of Egyptian Christians out at a time of tension with Muslims . Pope Shenouda III is to be buried Tuesday , a Coptic church spokesman says . Comment: