Algeria's Grand Mosque, the world's third-biggest and Africa's largest, hosted its first public prayers this week a year and a half after construction was completed. Known locally as the Djamaa El Djazair, the modernist structure extends across 27.75 hectares and is smaller only than the two mosques in Makkah and Madinah in Saudi Arabia, Islam's holiest sites. The mosque's interior, in Andalusian style, is decorated in wood, marble and alabaster. It features six kilometres of Koranic text in Arabic calligraphy, along with turquoise prayer mats. The mosque aims to be an important theological, cultural and research centre, and the complex includes a library that can host a million books. Featuring geometric architecture, it also boasts the world's tallest minaret – 267 metres – fitted with elevators and a viewing platform that looks out over the capital and the Bay of Algiers. The tallest such structure had previously been a 210-metre minaret in the Moroccan city of Casablanca. But it has all come at a cost of over $1 billion in public money, according to finance ministry figures. The seven-year construction work was completed in April 2019, three years behind schedule, and the company in charge, China State Construction Engineering (CSCEC), brought in labourers from China. Five imams preside over the mosques and five muezzins are responsible for conducting the call to prayer, said Kamel Chekkat, a member of Algeria's ulema association of Muslim scholars. He told AFP that the mosque would be tasked with "regulating and harmonising fatwas with Algerian life". A multidisciplinary study and research group will examine the Koranic text and "its keeping with the times and above all, with science," he added. "The idea is that the Grand Mosque will be a place for combating all types of radicalism, religious and secular," Mr Chekkat said. President Abdelmadjid Tebboune had been expected to inaugurate the mosque's prayer hall – whose maximum capacity is 120,000 – at the event on Wednesday, the eve of the birthday of the Prophet Mohammed. But Prime Minister Abdelmadjid Djerad and members of the government opened the hall in Mr Tebboune's stead, after the president was hospitalised and then flew to Germany for treatment amid a Covid-19 scare. Mr Tebboune had gone into self-isolation on Saturday following reports of suspected coronavirus cases among his aides. It was unclear how many people were allowed to attend the prayers amid the pandemic. But its critics say the mosque is a vanity project for former president Abdelaziz Bouteflika, who was forced out in April last year after mass street protests against his two-decade-long rule. "There is a mosque in almost every neighbourhood," said Said Benmehdi, an Algiers resident in his seventies, whose two children are both unemployed. He told AFP bitterly that he would have preferred for the "state to build factories and let young people work". Sociologist Belakhdar Mezouar said the mosque "was not built for the people". It is the "work of a man [Bouteflika] who wanted to compete with neighbouring Morocco, make his name eternal and put this construction on his CV, so he could get into paradise on judgment day," he said, adding that his opinion was widely shared. Nadir Djermoune, who teaches town planning, criticised the "ostentatious choice" of such mega projects at a time when he said Algeria needed new health, education, sporting and recreational facilities. The mosque is "isolated from the real needs of the city in terms of infrastructure", he said. The most positive point, he said, was its modernist concept, which "will serve as a model for future architectural projects".