Published: Jan 02, 2012 8:32 PM EST

RUSKIN, Fla. (AP) - A 12-year-old boy who police say was wounded by celebratory New Year's gunfire remains hospitalized in Tampa in critical condition.

Sandra Duran told reporters Monday that a bullet falling from the sky early Sunday pierced her son Diego's skull and lodged behind his right cheekbone. Duran said doctors are waiting for swelling in the boy's brain to subside before attempting to remove the bullet.

Diego Duran and his family were watching fireworks outside their rural Ruskin home when he fell to the ground with a head wound.

The Hillsborough County Sheriff's Office says no one nearby was firing a gun and the bullet could have been fired miles away. Detectives are asking the public for tips about people firing handguns or rifles into the air around 1 a.m. Sunday.