Two police officers were fatally shot over the weekend in Utah and Ohio, becoming the first officers killed in the line of duty this year.

Attorney General Loretta E. Lynch said Tuesday that she was “appalled and deeply saddened by the recent shooting attacks against law enforcement officers” in both states as well as an earlier ambush in Philadelphia that severely wounded an officer there.

“These heinous assaults are reminders of the difficult jobs that our brave law enforcement officers perform every day and of the dangers that they willingly face in the service of their communities,” Lynch said in a statement.

One of the officers was shot and killed chasing someone who had fled a traffic stop, while the other was found dead after authorities received a report of a threat to police, according to law enforcement officials. They were the first law enforcement officers killed in 2016, a grim milestone that came six weeks earlier than the first killing of an officer last year.

More officers died in 2015 than the year before, rising to 124 officers last year from 119 in 2014, an increase that was due to spikes in traffic-related deaths and job-related illnesses such as  heart attacks, according to the National Law Enforcement Memorial Fund, a nonprofit  that tracks line-of-duty deaths.

The number of officers fatally shot fell last year, as did the number of officers killed in “felonious incidents,” the memorial fund said in a report released last month. There were 52 officers killed in felonious incidents, down from 61 deaths a year earlier, and 42 officers fatally shot, down from 49 the year before. The number of officers fatally shot is significantly down from the 1970s, when an average of 127 officers were shot and killed each year. Between 2000 and 2009, an average of 57 officers were fatally shot each year.

Police officers have described feeling increasingly anxious amid ongoing protests over how law enforcement uses deadly force, though officers have been concerned about being targeted for ambushes and violence since long before these demonstrations focusing on policing began to recur nationwide.

Ambush attacks accounted for 15 officer deaths in 2014, according to the memorial fund, the most common type of felonious officer death that year and matching 2012 for the most such deaths in a decade. A study released last year by the Department of Justice looking at ambushes or planned attacks between 1990 and 2013 said that concerns about violence targeting officers were on the rise. That study also said that while the number of ambush attacks remained steady over the period examined, the proportion of fatal attacks attributed to ambushes increased.

Thomas Cottrell, an Ohio police officer, was found dead Sunday night after a woman called 911 call to tell authorities about a threat to police in Danville, a village about 70 miles northeast of Columbus.

“She said that her ex-boyfriend Herschel Ray Jones had left with weapons and was looking to kill an officer,” Knox County Sheriff David Shaffer said in a statement.

A recording of the 911 call, posted online by WKYC, captures a woman saying that her ex-boyfriend had attacked and threatened her.

“Cops in Danville are in danger, too,” the caller said. “My ex-boyfriend’s out in camo looking to kill a cop. …H e’s got guns on him.”

Shaffer said that authorities made unsuccessful attempts to contact a particular Danville officer. A little less than 30 minutes later, as deputies from the Knox County Sheriff’s Office searched the area, they found Cottrell, an officer in Danville.

Cottrell was dead when authorities found him on the ground behind the village’s municipal building, and his gun and police cruiser were gone, Shaffer said.

Nearly two hours later, officials said they found the suspect, identified by Shaffer as Herschel Jones III, and took him into custody after a brief chase. They interviewed and released a woman found near the home where Jones was spotted, Shaffer said.

The Knox County Sheriff’s Office and the Ohio Bureau of Criminal Investigation are investigating Cottrell’s death. In a statement, Ohio Attorney General Mike DeWine, who oversees the bureau, called Cottrell’s death “an unspeakable tragedy.”

“His assassination is the latest reminder of how dangerous police work is and how the police are targeted for violence,” Jay McDonald, president of the Ohio Fraternal Order of Police, said in a statement.

Cottrell’s autopsy was being conducted Tuesday, said Chip McConville, the Knox County Prosecuting Attorney. He also said state investigators had taken evidence from four different places in Danville on Monday.

Earlier on Sunday, a police officer in Utah was shot and killed while looking for people who had fled from a car crash southeast of Salt Lake City, according to the Unified Police Department of Greater Salt Lake.

Douglas Scott Barney, 44, was fatally wounded after finding one of the two people believed to have fled the crash, authorities said.

Other officers headed to the area and police said the suspect, Cory Lee Henderson, 31, was fatally wounded in a shootout with officers. Another officer — 51-year-old Jon Richey — was shot once by a bullet that went through both legs, police said.

Barney was pronounced dead Sunday afternoon at Intermountain Medical Center, while Richey was brought there in serious but improving condition.

The Salt Lake City Police Department, which is investigating the incident, said late Monday that it had found and interviewed the other person believed to have left the car crash. This woman, described as the passenger in the car, was interviewed and released without any charges.

These deaths came more than a week after a Philadelphia police officer sitting in his cruiser was shot multiple times by an attacker who later claimed he carried out the attack after pledging allegiance to the Islamic State, authorities said. Officials are  investigating that shooting.