New Mexico authorities have decided to beef up security at mosques after a string of murders targeting Muslim men.

On Sunday, the Police asked for the public’s help in locating a “vehicle of interest” in their probe of four fatal shootings of the men whose slayings in Albuquerque over the past nine months are believed by investigators to be related.

Mayor Tim Keller said state authorities were working to provide an “extra police presence at mosques during times of prayer” as the investigation proceeds in New Mexico’s largest city, home to as many as 5,000 Muslims out of some 565,000 total residents.

The latest victim, police said, was gunned down on Friday night, in a killing that local Islamic leaders said occurred shortly after he had attended funeral services for two others slain during the past couple of weeks.

All three of those men, as well as the very first victim who was shot dead in November, were Muslim men of Pakistani or Afghan descent who resided in Albuquerque.

Police have given few details of the latest murder but described the first three killings as ambush shootings. Governor Michelle Lujan Grisham has characterized them as “targeted killings of Muslim residents.”

Police in New Mexico and federal agencies were probing the murders of four Muslim men to determine if the killings, the latest of which happened on Friday evening, were linked while the state’s governor described them as “targeted killings.”

Albuquerque Police Chief Harold Medina told reporters on Saturday that a “young man who is part of the Muslim community was murdered.”

The victim’s name and the circumstances of the murder were not disclosed. In the previous three cases, the victims were ambushed and shot without warning, police said.

Medina said the killing was possibly linked to the previous three murders.

Police in New Mexico had said earlier that the other three Muslim men murdered in the state’s largest city in the past nine months appeared to have been targeted for their religion and race.

“The targeted killings of Muslim residents of Albuquerque is deeply angering and wholly intolerable,” New Mexico Governor Michelle Lujan Grisham tweeted late on Saturday. She also said she was deploying extra state police officers to Albuquerque to assist in the investigation.

Two of those murdered men were members of the same mosque, who were shot dead in Albuquerque in late July.