Editor’s note: This is the first of a two-part series on how the sharp increase in violence in El Salvador is changing the daily lives of residents of the capital.

SAN SALVADOR, El Salvador — Hundreds of police officers, some wearing masks to protect their identities, sat in the large white church in Zacatecoluca, a short drive from the capital. They were joined by the country’s police chief, government ministers and the U.S. ambassador for what has become a familiar occasion: the funeral of a police officer murdered by gangs.

In 2015 more than 20 police have been killed by the country’s powerful Mara Salvatrucha and 18th Street gangs. At least six soldiers have also been killed this year. Violence is approaching the high levels seen before the criminal groups agreed to a truce three years ago.

During a single weekend in April, at least 34 people were murdered, 22 of them in a single day, April 19, the most violent 24 hours this year, according to official sources. With the truce over, some gang members have been returned to maximum-security prisons, where it’s believed they instructed smaller neighborhood units to kill two police officers apiece. The information regarding the gangs’ strategy was reportedly provided to police intelligence sources by informants.

The people in the Zacatecoluca church were there to mourn the death of Wendy Yamileth Alfaro Mena, 27, the first policewoman to be murdered. She was gunned down on the afternoon of April 20 as she left her home in Zacatecoluca to buy tortillas. Gang members had been watching her, according to police. It’s unclear if they were from the Mara Salvatrucha or the 18th Street gang, which has split into the rival Revolutionarios and Sureños, or Southerners.

At her funeral and again at a private ceremony afterward at which police presented Alfaro’s family with the flag that draped her coffin, her murder was described as a blow against all Salvadoran women and one that must drive the police and all Salvadoran society to continue la lucha, or fight, against the gangs.

“The gangs know that these actions demonstrate their willingness to attack the state, to attack the country and to show how strong they are,” said El Salvador’s Deputy Police Chief Howard Cotto. He said that violence and crime in El Salvador are getting worse and that “force must be met with force.”

As for the truce between the gangs that went into effect March 2012 and led to a marked reduction in murder rates, Cotto said, “We have been very clear that we do not agree with that.”

The truce, apparently brokered by intermediaries in the Catholic Church, had been seen as an example to follow for other countries with similar severe gang problems, like Honduras. Similar efforts championed by the bishop of San Pedro Sula in Honduras failed. The extent of the government’s role in agreeing to the truce remains unclear.

El Salvador’s then-President Mauricio Funes was adamant in March 2012 that “the government did not sit down to negotiate with gangs,” although he admitted it played a part “facilitating” the accord. There was an immediate dramatic drop in the murder rate after the truce. By the end of 2012, the national police had registered a 41 percent reduction in killings from the previous year — 2,576 compared with 4,371.

But it didn’t last.

According to Steven Dudley from Insight Crime, a U.S.-based foundation that tracks organized crime in the Americas, the agreement was “more of a violence interruption project than a truce.”

“It required the participation of police and trusted interlocutors with the gangs,” he said. “It fell apart when the government pulled its support from the project in June 2013 and named a new security minister. It slowly unraveled thereafter.”