An apparent homemade firework blew off at New York's Central Park on Sunday, which has injured a 19-year-old tourist. Police say the explosion was triggered when the young man jumped off a rock and stepped on the device. He suffered a severe foot wound and may face amputation.

Investigators say the object is more like a firework prepared for the Fourth of July celebrations, rather than a work of extremists designed to hurt civilians. The park remained open to visitors following the blast. But police are checking for any additional explosives in the park. Across the US, security has been beefed up especially on public places, as the country celebrates its Independence Day.