Coffee drinkers at several Twin Cities Starbucks locations will have to wait until 8 a.m. to get their morning jolt of java as stores adjust hours to open later in the wake of a string of armed robberies.

In the past month, gunmen have stormed into at least four Starbucks stores in Minneapolis, Richfield and St. Louis Park just as they opened.

The most recent heist occurred before dawn Thursday in St. Louis Park, when two men hit the coffee shop on Minnetonka Boulevard, near the intersection of Hwy. 7 and W. Lake Street. One displayed a black handgun and demanded money, according to police. As in other heists, the suspects got away with cash, police said.

No one has been arrested.

Nobody has been hurt in the holdups, some of which have occurred as early as 5:30 a.m. But in response, some Starbucks stores have delayed opening times a couple of hours. On Friday, a notice taped to the door of the Dinkytown store at 5th Street and 14th Avenue SE. alerted customers.

“We apologize for the inconvenience, but we have to change our store opening hours to 8 a.m.,” it read. “We appreciate your patience.”

Tim Cantway, who has managed the Dinkytown store for the past six years, said his store has not been robbed, but one in the nearby Cedar-Riverside neighborhood was hit Dec. 10. Police said a second store at 2000 Nicollet Avenue S. was robbed on Dec. 12.

Another Starbucks on the 7700 block of Lyndale Avenue in Richfield was hit on Dec. 21. In that holdup, a suspect made off with $1,189.

“Yesterday was the final straw,” Cantway said Friday. “It’s been unnerving for people. To keep people safe, I think this is the right choice. It will be much better opening later.”

The new hours will remain in place indefinitely, he said.