DAVAO CITY, Philippines — Tears welled in Clarita Alia’s eyes when she saw the three unmarked tombs, one on top of each other. “There they are,” she said as she stretched out her trembling hand, almost touching the cold, whitewashed concrete. “They’re all gone.”

“They” are Richard, Christopher and Bobby, three of Alia’s eight children who died one after the other at the hands of death squads in this city.

Richard, 18, was the first to be killed, in 2001, followed by Christopher, 16, that same year and Bobby, 14, the next year.

Their tombs in a hilltop cemetery are a testament, not only to the anguish of their 50-year-old mother, but also to the madness that for years has gripped Davao City, where death squads roam, hunting for suspected criminals and killing them.

Human rights groups said the killings have become an unwritten government policy to deal with crime, largely because of an ineffective criminal justice system and the tendency of the authorities to take shortcuts in the administration of justice.

What worries many Filipinos now is that the death squad phenomenon is appearing in other parts of the country. “If you want to kill anybody in the Philippines, now is the best time,” Dante Jimenez, chairman of Volunteers Against Crime and Corruption, said bitterly in an interview. His group has monitored the rise in extrajudicial killings in at least half a dozen cities recently and expects the situation to worsen.

It has never been established who the killers are, although there have been reports that they are former Communist guerrillas hired to rid cities of criminals, particularly drug pushers. In at least two cases, survivors said their attackers had been police officers.

The execution-style killings in Davao City - 72 victims so far this year, six of them children - are openly endorsed by local officials, strengthening the long-running suspicion that the death squads were formed by the government.

Although the mayor, Rodrigo Duterte, denied any responsibility in the creation of the death squads, he ran for re-election last year on a promise to eliminate criminals. The killings never stopped, and he has repeatedly admonished criminals to leave his city or risk death.

Davao, a southern city with more than one million people, is one of the country’s highly urbanized cities. Its crime situation has been affected by a recent increase in the number of gangs and street children. Illegal drugs are common.

Bernie Mondragon, an official of the Coalition Against Summary Executions, a nongovernment group, said extrajudicial killings “are now the unwritten state policy in dealing with crime.”

In January, when 34 people died and the killings were at their worst, Davao’s police force was chosen as the country’s bestfor 2004. Yet 107 people were killedthat year and, according to Amnesty International, none of the 320 murders in the city since 1998 has been solved.

Last year, in an act that human rights groups interpreted as an endorsement by President Gloria Macapagal Arroyo of extrajudicial killings, she named Duterte as her adviser on crime. When Arroyo was later criticized, her officials said the government would never support extrajudicial killings.

Leopoldo Bataoil, a spokesman for the national police, said that the government treated extrajudicial killings as crimes and that it was doing its best to stop them. “We will never tolerate vigilante killings,” he said in an interview.

The U.S. State Department reported on the killings in its human rights report released last month, while Amnesty International denounced them in January.

Extrajudicial killingswere common in the Philippines during the Marcos dictatorship, and have returned with ferocity in the last five years.

Killers, usually working in tandem on a motorcycle, select victims who are usually petty thieves such as cellphone snatchers or drug pushers. Many victims are juvenile delinquents. In one case in Davao, a young man accused of stealing a cellphone was shot to death just as he stepped out of the police station.

Clarita Alia’s children had had scrapes with the law. One had been implicated in a murder, although the case had been dropped; another had been accused of theft. But she denied that they had been criminals.

“Let’s assume that they were criminals. Is killing them the answer?” she asked. “Why is it so easy for the government to kill poor people like my children? Where is due process?”

For many officials, due process is precisely the problem. “These killings happen because the criminal justice system is not working,” said Tomas Osmeña, the mayor of Cebu City, a major city in the central Philippines where dozens of suspected criminals have been killed since the beginning of the year. Osmeña complained about corruption in the judiciary and the police.

“The criminal justice system is too tedious,” said Conrado Laza, the police chief of Davao. “Cases move slowly. So many complainants probably just give up and take matters into their own hands and exact revenge.”

Defects in the judiciary have allowed death squads practically to supplant the criminal justice system, said Pilgrim Guasa, coordinator of Tambayan, a group that helps juvenile delinquents in Davao. Worse, she said, the authorities “do not have any sense of accountability whatsoever. They treat these killings as crime prevention, not crime in itself, so they don’t feel accountable.”

When Osmeña, the Cebu mayor, said this year that he wanted the police “to be more aggressive” against crime, hunter teams emerged overnight to hunt for suspected criminals.

While Osmeña denied in an interview having any knowledge or official sanctioning of those hunter teams, he admitted to having told law enforcers that “if you encounter a crime in progress, don’t be shy. Pull the trigger and I’ll give you a bonus.”

Osmeña said as a result of the vigilante killings, crime in Cebu had gone down. He takes pride in the “very strong support by the public” for these killings. “People congratulate me,” he said.

Carlos H. Conde