VATICAN CITY; Pope Benedict XVI, under fire as the Roman Catholic Church grapples with snowballing paedophilia scandals, used the popemobile for the first time on a Palm Sunday to open the church's solemn Holy Week in St Peter's Square. The 82-year-old pope, appearing in good health, used the iconic white vehicle to criss-cross the sun-drenched square, waving to tens of thousands of pilgrims. In previous years he has carried out the tradition on foot. Vatican spokesman Federico Lombardi told reporters the change was aimed at making the pope "more visible" to the throngs. Lombardi also noted that Palm Sunday is the start of a busy week for the pope leading up to Easter, Christendom's most joyous observance marking the Resurrection of Christ. The pope has come under intense pressure in recent weeks as paedophile priest scandals have swept several countries including his native Germany where he was accused of failing to bar the transfer of a predator priest. On Thursday the head of the world's 1.1 billion Catholics came under fresh scrutiny over the case of an American priest accused of abusing up to 200 deaf boys who was never disciplined. Lombardi said that Benedict had not been "weakened" by the allegations, which have prompted some commentators to suggest that he could be forced to resign after five years on the throne to which popes are elected for life. In the 2,000-year history of the papacy only two popes have resigned, in 1294 and 1415. The conservative Benedict, who previously headed the Vatican department that safeguards Church doctrine and morals, has continually spoken out and apologised for the "heinous crime" of child sex abuse by priests, meeting victims in the United States and in Australia. Security concerns may also have prompted the decision to use the popemobile, the white bulletproof vehicle introduced for Benedict's predecessor John Paul II. Today, Benedict blessed the pilgrims waving palm branches. Palm Sunday recalls Jesus' triumphal entry in Jerusalem preceding his arrest and crucifixion.