A small improvised explosive device detonated outside an Upper East Side Starbucks early Monday morning, shattering the coffee shop’s windows and raising fears of terrorism.

The bomb tore a hole in a wooden bench outside the coffee chain’s outpost at Third Ave. and E. 92nd St. when it exploded at 3:30 a.m.

No one was injured in the blast, but it terrified residents who had been fast asleep early on Memorial Day. (NY Daily News)