Investigators were searching on Tuesday for clues to the motive behind the bombings and attempted bombings in New York and New Jersey over the weekend and to determine whether the Afghanistan-born suspect had accomplices or was radicalized overseas.

Ahmad Khan Rahami, 28, was arrested on Monday in Linden, New Jersey following a dramatic gun battle with police after they were summoned by a neighborhood bar owner who thought the bearded man sleeping against his closed tavern's front door in the pouring rain resembled the bombing suspect.

Rahami and two police officers were wounded in the exchange of gunfire.

Authorities did not offer any immediate information on the possible motives of Rahami, who was charged by Union County prosecutors with five counts of attempted murder in the first degree and two second-degree weapons charges.

More charges were expected to be brought against Rahami in federal court. New York's mayor called the bombing that injured 29 people in the bustling Chelsea district "an act of terror."