Prayers of thanksgiving mingled with quiet sobs on Tuesday as family members of people slain during former Philippine president Rodrigo Duterte's drug war gathered for a mass celebrating his arrest on charges of crimes against humanity..Widows and mothers carefully placed framed photographs of their dead husbands and sons in front of the altar at the Sacred Heart Parish in a Manila suburb, casualties of a crackdown that activists say killed tens of thousands of mostly poor men..The women said Duterte's arrest on Tuesday morning by police serving an International Criminal Court (ICC) warrant was an "answered prayer"..Father Flaviano Villanueva, a Catholic priest and fierce opponent of the drug war, recalled in his homily the despair the relatives felt while waiting for justice, likening news of Duterte's arrest to a long-closed prison cell finally being flung open.."I hope this arrest will pave the way for the complete healing of our country, for people to remember that justice will prevail," Villanueva told AFP after his sermon..Luzviminda Dela Cruz, whose 19-year-old son was killed by police after a raid on a relative’s house in 2017, told AFP she felt relieved that "my son has now achieved justice".."I feel a kind of happiness that I cannot explain. I have been praying for this every day," said Dela Cruz, who wore a sky-blue shirt printed with the word "justice"..'The Lord listens' .Duterte was president from 2016 to 2022 and ICC prosecutors in The Hague say the number of those killed in his drug war ranges from 12,000 to 30,000..He and his lawyers have questioned the legality of the ICC warrant but Duterte has also said he offered "no apologies, no excuses" for his actions while president..For Sofia Joveres, a widow who participated in the mass, Duterte's arrest was "proof that the Lord listens to us", although she said she was "not completely happy".."I honestly don't feel that happy because, even if Duterte was arrested, it can't bring back the life of my husband that they heartlessly took away in the drug war," the 45-year-old said through tears..Joveres said her husband was forcibly brought out of their home in the capital by about a dozen uniformed and plainclothes police officers in 2016. .She said her neighbours told her that police ordered her husband to run as fast as he could before gunning him down..Joveres said one of her prayers in Tuesday's mass was for Duterte to own up to his responsibility and pay for the crimes committed in the name of his drug war.."It's important that Duterte admits that, because he was the root of all the pain and violence that we endured," Joveres said.