A Catholic bishop has warned people flocking to cemeteries to observe All Souls' Day and All Saints' Day this week to be on their guard against fake priests. "Don’t be deceived by people who offer to bless graves, pretending that they are priests… unless of course you know them," Bishop Leonardo Medroso of Tagbilaran wrote in an article posted on the bishops' conference website. Bogus priests roam cemeteries during these days asking for donations in exchange for their blessings, he wrote. He suggested people ask priests for their celebret, a letter from a bishop or religious superior confirming that the bearer is a priest, before asking for blessings. Archbishop Socrates Villegas of Lingayen earlier reminded the clergy against "commercializing" the sacraments during the observance of All Souls' Day and All Saints' Day, known as Undas in the Philippines. "It is prohibited to collect any donations for individual blessing of graves. It is prohibited to conduct ‘special blessing of graves’ for friends of priests and benefactors of the Church over the October 31 to November 2 period," the archbishop said. The observance of Undas, from the Spanish andas, or Day of the Dead, has become a major family affair in the Philippines, a tradition introduced by early Spanish friars. On November 1 and 2, which are public holidays, tombs are cleaned or repainted, candles are lit and flowers are offered. Filipino families camp in cemeteries and spend a night or two near their relatives' tombs, playing card games, eating, drinking, singing and dancing.