New York City authorities say the Boston Marathon bombers were planning a second attack at New York's Times Square.

New York Mayor Michael Bloomberg and New York Police Commissioner Raymond Kelly said in a joint news conference on Thursday that New York City was next on the list of targets of Tamerlan and Dzhokhar Tsarnaev.

Kelly said that in the process of fleeing after carrying out the Boston Marathon bombing last Thursday, the Tsarnaev brothers hijacked a car and decided on the spot to drive to New York and launch an attack with their remaining explosives.

Kelly said that the brothers had five pipe bombs and a pressure-cooker explosive in the hijacked car.