The U.S. Embassy in Egypt condemned the terrorist attacks that hit Saint George's Church in Tanta and St. Mark's Cathedral in Alexandria, in an official statement released Sunday. The U.S. Embassy denounced what it described as "heinous and reprehensible" attacks against peaceful worshipers during church ceremonies on one of the holiest days of the Christian year, according to the statement. "Our thoughts and prayers go out to the victims of this horrific attack. We express our deepest condolences to the families and friends of the victims," the statement read. "The United States stands firmly with the Egyptian government and people to defeat terrorism." Two deadly bombings took place on Sunday at two major churches during the celebrations of Palm Sunday, leaving dozens killed and injured. Alexandria's attack has targeted the Coptic Patriarch, Pope Tawadros II, who was leading Palm Sunday's prayers at Alexandria's cathedral. According to security sources, a suicide bomber has blown himself at the cathedral's back door, killing 18, and about 40 were injured. Security forces detained two suspects believed to be responsible for the bombings. The explosions came 20 days ahead of the scheduled visit of Pope Francis of the Roman Catholic Church to Egypt.