Church bells rang out across Moscow on Sunday as Orthodox faithful gathered at the main cathedral to pray for the \"correction\" of a group of feminist punks who burst into the cathedral earlier this year in a political stunt which led to their arrest.. City officials said they expected tens of thousands to join a mass outdoor prayer led by Patriarch Kirill at the Moscow cathedral at 1000 GMT while other Orthodox houses of worship across the country held similar events. The Church said the prayer would call for \"the correction of the defilers of holy shrines and the good name of the Church.\" It added the patriarch would call for protection against those who \"burst into cathedrals\" and released a film on its website showing various celebrities calling on Russians to unite in Orthodox faith. \"When Communism disappeared, the last stronghold of Russia\'s genetic code -- its key -- became Orthodoxy,\" Oscar-winning film maker Nikita Mikhalkov said in the film. The balaclava and miniskirt-clad members of the protest group Pussy Riot burst into the Christ the Saviour Cathedral in February and belted out bits of a song denouncing the Church\'s open support for president-elect Vladimir Putin. They face seven years in prison. The incident received little attention at first and the group was released after being booked. But the Church soon turned the incident into a rallying call and other Putin backers joined its ranks as they sought to build a movement capable of standing up to the protests that preceded the ex-KGB agent\'s election to a third term. The patriarch led a morning service at the cathedral and was later due to bring out icons and other relics the Church said were \"defiled\" by the band. Some organisers said they expected as many as 40,000 people from across Russia to descend on the onion-domed cathedral -- rebuilt from the ground up under Kremlin instructions a decade ago -- to hear the patriarch speak. \"We have received a lot of requests from dioceses asking us to help them come and pray with us,\" Church spokesman Vladimir Legoida said ahead of the event. \"There will be hundreds of buses. Maybe even more.\" City officials said they had dispatched nearly 2,000 police to the site to both handle the crowds and make sure that scuffles do not break out between the faithful and the band\'s most fervent supporters. Nearly 30 Pussy Riot fans were booked on Thursday after rallying outside a Moscow court house that extended the pretrial detention of three group members through late June.