Adding to the feeling of vulnerability, Anchorage has had 25 homicides this year. That is the same number the city had for the entire year in 2015. Even though the number is high, the police point out that 1995, with 29 homicides, had the highest numbers in the past two decades.

With 15 homicides since late June, the Anchorage Police Department issued an unusual public advisory last week urging residents to be “extra aware” of their surroundings, noting that crimes often increase at night and early in the morning.

“A.P.D. wants to remind our citizens to be cautious when they are out during these hours, especially if they are in isolated areas like our parks, bike trails or unoccupied streets,” the Police Department wrote. “If you plan to be out late at night, make sure you travel with several friends and not alone.”

Chief Chris Tolley played down the significance of the advisory, saying that the police often remind the public to be safe, sometimes through a text messaging system.

This year, the police issued a similar safety alert after a series of car break-ins and thefts, Chief Tolley said. The goal was the same in this week’s advisory, to inform the public.