VALLETTA (Reuters) - Thousands of mourners at a funeral on Friday for slain Maltese anti-corruption blogger Daphne Caruana Galizia heard a plea for the protection of journalistic freedoms and a warning to her unknown killers that they face  the justice of God.  The island s president, prime minister and opposition leader, all targeted in Caruana Galizia s writing, stayed away from the private ceremony, but European Parliament President Antonio Tajani attended as a guest of the family.  The island observed a day of mourning and flags flew at half mast in Brussels during the funeral at Malta s biggest church, near the capital Valletta and two miles from the site where the 53-year-old was killed by a car bomb as she left her home on Oct. 16.  Archbishop Charles Scicluna, who led the funeral mass, addressed the unknown killers, saying,  However hard you try to evade the justice of men, you will never escape from the justice of God. Repent before it is too late.  He then told journalists not to be afraid.   I encourage you never to grow weary in your mission to be the eyes, the ears, and the mouth of the people ... We need people in your profession who are unshackled, who are free, intelligent, inquisitive, honest, serene, safe and protected.  Reflecting concern in neighboring countries about possible failings in democracy and the rule of law in Malta, the European Union vowed earlier on Friday to make sure its smallest state found the  barbarous  killers.  Tajani was also due to visit the offices of a newspaper for which she worked as a contributor, and Caruana Galizia s family was invited to a sitting in parliament to commemorate her.  The island s government is offering a one million-euro ($1.16 million) reward for information about the culprits and has asked the U.S. Federal Bureau of Investigation (FBI) to help. But the Caruana Galizia family refused to endorse the reward, called for the resignation of the prime minister, the police commissioner and the attorney general, and insisted there could be no justice without institutional change.  Their calls have been echoed by opposition leader Adrian Delia, who said the police commissioner and attorney general s failure to act when Caruana Galizia revealed corruption created the circumstances leading to the assassination. Mourners applauded, made  V  for victory signs and sung the national anthem as the coffin was carried to a hearse. Some chanted  Justice .  Caruana Galizia s husband and three adult sons stood solemnly, occasionally hugged by mourners. Malta s chief justice and former prime ministers Lawrence Gonzi and Eddie Fenech Adami also attended. A household name in Malta, Caruana Galizia was well-known for stirring up passions and dividing opinion. Her murder shocked the tiny country and was condemned by all political parties, but controversy continued on the day of her burial. Maltese news websites reported several critical Facebook posts including one referring to a demonstration outside police headquarters planned by a group of NGOs which is demanding the commissioner s resignation.   You d have to wonder why you never get a truck mowing people down here in Malta. Who knows? Maybe that will happen at Sunday s protest. I d love to see them crushed in the middle of the road,  one read. ($1 = 0.8607 euros) 