New Jersey police: 6-year-old dies a day after being shot -- by a 4-year-old

(CNN) -- A 6-year-old New Jersey boy has died after being shot in the head by a 4-year-old playmate as their parents stood in the yard nearby, a local police chief said.

Brandon Holt was pronounced dead at 5 p.m. Tuesday at Jersey Shore University Medical Center in Neptune, according to Toms River police Chief Michael Mastronardy.

It was the second incident in the United States in recent days involving young children accidentally shooting others.

Brandon was playing in and around the 4-year-old's Toms River home on Monday evening when the younger child left the yard and went inside, police explained.

"The 4-year-old ... retrieved a rifle within the house, a .22-caliber rifle, came outside," Mastronardy told reporters earlier Tuesday. "... A shot went out and the 6-year-old was struck in the head."