WASHINGTON -- The White House said Thursday that a small explosion in New York City's Times Square "doesn't appear to be terrorism" but that it would follow the investigation closely.

Asked whether it was a terrorist act, spokeswoman Dana Perino replied: "It doesn't appear to be, but again investigation is still ongoing."

"It's a little bit early to determine exactly what happened, but we are thankful that it appears that no-one was injured or killed in this incident. But we'll keep an eye on it," she said.