Nashville was on edge Sunday as authorities searched for what a local police official described as a pair of “cold-blooded killers” who allegedly gunned down two people celebrating a birthday.

Authorities said the suspects in Friday's shootings may be linked to a string of recent crimes, including four attempted robberies and the killing on Tuesday morning of 31-year-old Kendall Rice as he walked to the bus stop to go to work.

“It’s definitely scary,” said Nashville resident Hannah Thompson. “It struck a lot of fear in me and makes me nervous to get home at night."

A makeshift memorial for Jaime Sarrantonio at The Cobra in east Nashville, Tennessee. Courtesy of The Cobra

Police identified Friday’s victims as Bartley Teal, 33, and Jaime Sarrantonio, 30, both of Nashville. They were killed after leaving The Cobra — a music venue and bar in east Nashville — around 3 a.m. (4 a.m. ET) and heading to a nearby convenience store.

“They then walked back to The Cobra bar parking lot where they and two other persons — a man and a woman — were confronted by these two individuals with at least one gun," Nashville police spokesman Don Aaron said. "Mr. Teal reported it was a robbery and he was fatally shot."

He said a short time later Sarrantonio was fatally shot.

“These are just two senseless cold-blooded homicides,” Aaron said, adding that the motive for Sarrantonio’s shooting remained under investigation.

A police statement said the two other robbery victims with Sarrantonio and Teal were not shot.

Friday was Teal’s 33rd birthday, NBC affiliate WSMV reported.

Kendall Rice. Nashville Police Department

Nashville Metro Police Department Commander David Imhof told reporters that timing and suspect and vehicle descriptions led investigators to believe Friday’s killings may be connected to Rice’s fatal shooting and four attempted robberies, according to The Tennessean.

"We are investigating these cases as possibly related," Nashville police spokeswoman Kristin Mumford told NBC News. "There are similarities, but have not been definitively connected."

During one of the attempted robberies, the wife of a crew member of the band OneRepublic was shot in the back while she walked her dogs, the band said in a video on Twitter.

She “lost her spleen, it hit her spine, she’s now in a wheelchair and going through multiple surgeries,” the band’s frontman, Ryan Tedder, said in the video.

Another robbery victim, Ryan Noble, said he was walking with friends toward The Cobra on Thursday when two men pulled a gun on the group. Noble said during the robbery he saw a silencer on the end of the gun.

"I guess we're just lucky that nobody pulled the trigger." Noble said.

The assailants took Noble's wallet, which was later recovered with nothing removed. They also took the purse, which was also recovered, of one of Noble's friends and the phone of another.

Noble, who was hit in the face with the gun during the robbery, said he was shocked when he learned that others who had been robbed were killed during the confrontation.

"I still don't really know if I've processed it completely, you know," Noble said. "Just feeling terrible for those people."

Police described the suspects as two black men in their 30s — one of whom has dreadlocks — who were seen in a small Chevrolet.

BREAKING: The two murderers who killed a man and woman outside Cobra Nashville bar, 2511 Gallatin Ave, at 3:26 a.m. today during a robbery fled in this small Chevy car. Any information? Please call Crime Stoppers at 615-742-7463 pic.twitter.com/rXKtzd0FG1 — Metro Nashville PD (@MNPDNashville) August 17, 2018

The spate of shootings left the city rattled. The Cobra closed its doors Saturday and held an event for friends and family of Teal and Sarrantonio, while police warned residents to remain vigilant.

“We’re obviously telling folks to be in groups, be careful, be very cognizant of your surroundings and of what’s going on,” Imhof said.

CORRECTION (Aug. 20, 2018, 7:50 a.m.): An earlier version of this article misspelled the last name of one of the victims. She is Jaime Sarrantonio, not Sorrentino.