Pope Celebrates Easter Mass in Packed St. Peter’s SquareTens of thousands of faithful have undergone heavy security checks to enter St. Peter’s Square to participate in Easter Sunday Mass celebrated by Pope Francis. \n\nFrancis opened Easter festivities with a Tweet to his global flock: Pilgrims from around the world and Italy gathered in the square decorated with spring flowers to hear Francis deliver the traditional “Urbi et Orbi” (to the city and to the world) Easter message from the central balcony of St. Peter’s Basilica. \n\nSecurity precautions included bag checks and metal detector wands for everyone entering the square. The Via Conciliazione avenue leading to the Vatican as well as smaller adjoining streets were closed to traffic. On Saturday, the pontiff led an Easter vigil service, baptizing eight adults, including a formerly undocumented Nigerian migrant beggar who became a hero when he disarmed an Italian thief wielding a cleaver. The baptism took place during a long Holy Saturday, or Easter eve, Mass for 10,000 people in St. Peter's Basilica. The church, the largest in Christendom, was dark at the start of the service before lights were turned on, signifying the passage from darkness to light when the Bible says Jesus rose from the dead. The pope traditionally welcomes new members of the church during the Saturday night service. This year, among those he baptized was John Ogah, 31, whom Italian newspapers last year dubbed the "migrant hero" and held up as an example of bravery and good citizenship. Ogah was begging for change outside a supermarket in a Rome neighborhood where many migrants live last September when he\nstopped a 37-year-old Italian who had just held up the store with a cleaver and was getting away with about 400 euros, according to the Catholic television station TV2000. The Nigerian, who did not have permission to stay in Italy, held the man down until police arrived and then left the scene, fearing it would be discovered he did not have documents, according to La Repubblica newspaper. Police using footage from surveillance cameras tracked him down and rewarded him by helping him get legal permission to stay in the country. An Italian Carabinieri police captain who worked in the neighborhood, Nunzio Carbone, was his godfather, or sponsor, at Saturday's baptism service. Carbone and his fellow police officers helped Ogah get his immigration papers. The Nigerian now works as a stockman at a warehouse for a charity organization. The other newly baptized at the service came from Albania, Peru, Italy and the United States. Francis has made defense of migrants a key part of his papacy. The Associated Press contributed to this report.