Emily Soriano was doing laundry this week when a friend rushed into her house with news about their yearslong quest for justice.
In December 2016, gunmen stormed into a house in their poor neighborhood north of Manila and started shooting. They killed seven people, including three children and a pregnant woman. Ms. Soriano and her friend, Isabelita Espinosa, each lost a son, both teenagers.
To the victims’ families, the massacre seemed senseless, like thousands of other extrajudicial killings carried out during former President Rodrigo Duterte’s so-called war on drugs. Ms. Soriano and Ms. Espinosa have long held him responsible for the deaths of their sons —Angelito Soriano, 15, and Sonny Espinosa,16 — whom they say were innocent.
Mr. Duterte’s arrest on Tuesday, on accusations of crimes against humanity, was a major milestone toward accountability, the women said.
“What matters to me now is that justice is served,” Ms. Espinosa said. “And that we don’t allow these butchers and tyrants to remain in power. We must fight back.”
While he was in office, Mr. Duterte publicly encouraged the violence, which rights group say left tens of thousands dead. He promised immunity to the police officers who targeted people whom the authorities described as only “drug suspects.” Many were also killed by vigilantes.
Mr. Duterte rose to the presidency campaigning on his law-and-order credentials. He began his deadly antidrug campaign in the city of Davao, where he was the mayor for years and is accused of running a so-called death squad.
Between 2001 and 2007, Clarita Alia said four of her sons — all teenagers accused of petty crimes — were killed at Mr. Duterte’s behest. Over the past two decades, she became a symbol of protest against the killings in Davao, where speaking against Mr. Duterte was once unthinkable.
“I’m happy that he’s been jailed,” Ms. Alia said. “Now, he will feel what the people he hurt felt.”
Mr. Duterte was arrested in Manila on Tuesday after the International Criminal Court issued a warrant accusing him of crimes against humanity. Hours later, he was flown to The Hague, where both the I.C.C. and its detention facilities are based.
He is expected to make his first appearance in court on Friday, according to a court official. But his trial is not expected to start for months.
In the warrant, three judges of the court wrote that they had been presented with evidence that led them to believe Mr. Duterte was personally responsible for the killings and the attacks that were “both widespread and systematic.”
Mr. Duterte has argued the I.C.C. has no jurisdiction in the Philippines because he withdrew his country from the court while he was president. But in the warrant, the judges wrote that they were looking at extrajudicial killings while Manila was a member of the court. His supporters have denounced his arrest and handover to the I.C.C. as political persecution by the current president, Ferdinand R. Marcos Jr. Mr. Marcos has said he was complying with Interpol, which posted the I.C.C. warrant.
In Davao, Mr. Duterte’s stronghold, red ribbons with the words “Bring Duterte Home” were on display in many parts of the city. Some residents had stuck his photos on their vehicles in a show of support.
Ronald Camino said only criminals were angry with Mr. Duterte. “Those who do good are the ones being arrested,” he said.
In the Manila region, Ms. Espinosa got the news of Mr. Duterte’s arrest in a text message. Soon, she and Ms. Soriano were knocking on neighbors’ doors and gathering relatives of other drug war victims. Six other women joined them and hundreds of others that afternoon and lit candles to mark the arrest of Mr. Duterte.
During that rally, in nearby Quezon City, Ms. Espinosa wept for her son.
Ms. Soriano said she shares a birthday with Mr. Duterte, who will turn 80 on March 28. “I want to tell him: ‘I’m happy, this is a gift for me. But for you, it’s bad luck because you’ll be celebrating your birthday in jail.’”
But some Filipinos struggled to process their emotions.
Rodrigo Baylon’s son Lenin was killed by a stray bullet during a shootout in Caloocan in 2016, three days before he turned 10.
Celebrating Mr. Duterte’s arrest, Mr. Baylon said, also meant reliving that horrific event. At the time, Mr. Duterte’s chief of police, Ronald dela Rosa, who is now a senator, dismissed Lenin’s death as collateral damage in the drug war.
“Is this what they call justice?” Mr. Baylon said. “And will justice really come from the I.C.C.?”
He questioned why a foreign court, not the Philippine government, was holding Mr. Duterte accountable.
“Isn’t the government supposed to help people like us?” Mr. Baylon said.
Marlise Simons contributed reporting from Paris.
