Boston police on Saturday said an off-duty officer shot and killed a knife-wielding man after the suspect chased two people into a Chick-fil-A restaurant and tried to stab them.

Police Commissioner Michael Cox said the off-duty officer confronted the attacker around 5:30 p.m. at the fast food restaurant in the city’s swanky Back Bay neighborhood.

Authorities said the officer identified himself as a cop and ordered the suspect, whose name hasn’t been disclosed, to drop the knife.

“The individual did not comply,” Commissioner Cox said, prompting the off-duty officer to open fire to “stop the threat.”

Authorities said the wounded suspect was rushed to the hospital, where he died.

Police have yet to share the off-duty officer’s name.

Both Commissioner Cox and Boston Mayor Michelle Wu, a Democrat, praised the officer’s actions while expressing sorrow for the slain attacker.

“My condolences and all of our thoughts are with the family of the individual whose life has been lost,” Ms. Wu said.

• Matt Delaney can be reached at mdelaney@washingtontimes.com.