Updated

Investigators are looking into similarities between an early morning explosion at a Starbucks coffee shop in Manhattan's Upper East Side and others throughout the city in the past four years.

NYPD Commissioner Ray Kelly told reporters an explosive-like device went off outside the store at the intersection of 92nd Street and Third Avenue at about 3:30 a.m. Monday.

No injuries were reported.

Kelly said the bomb exploded around the same time of day as a May 2005 explosion at the British consulate, another at the Mexican consulate in October 2007 and one at the Times Square military recruiting station in March 2008.

A bicyclist was seen in the area prior to the previous bombings. Police have yet to see what, if any, security camera footage is available, Kelly said.

"We don't know the motive," Kelly said. "Obviously it is a cause for concern, but we're going to do an in-depth investigation."

Kelly said there was no call to police prior to the explosion, while seven calls to authorities immediately followed the blast, MyFOXNY.com reports.

No structural damage to the store was reported. Seven nearby residents were briefly evacuated following the explosion, MyFOXNY.com reports.

Kelly said the explosive appears to have been placed on the seat of a bench outside the coffee shop, but it was unclear what kind of container it was in. He said investigators would examine the remains to determine what kind of explosive it was and added it was possible it was some kind of firework.

Police also investigating whether the Starbucks, a few blocks from the Guggenheim Museum, was the intended target.

Jordan Kovnot, a 26-year-old law school student who was briefly evacuated following the explosions, told the Daily News, "I heard a giant noise — a big, giant noise, like a crash — and there was a flash."

Click here for more on this story from MyFOXNY.com.