Aftermath of the Starbucks Bombing

Mayor Bloomberg says police are checking security cameras to investigate who's responsible for an explosion at an Upper East Side coffee shop this morning.

BLOOMBERG: No real damage, certainly no injuries. Could have killed somebody. So there's somebody with a sick mind out there. Maybe more than one and we're looking for them.

REPORTER: The bomb went off around 3:30 in the morning, outside a Starbucks at 92nd Street and Third Avenue.

Police Commissioner Ray Kelly says investigators are looking into the similarities between the explosion and others that have taken place in the city over the last four years.

The blast occurred around the same time as an explosion at the British consulate in May 2005, another at the Mexican consulate in October 2007 and one at the Times Square military recruiting station in March 2008.