LOS ANGELES (TIP): A three-year-old boy in the US has shot and killed his 18-month-old brother with a handgun, adding to the spate of such tragic incidents in the country in the past two months. The boy died after he was shot in the head by his elder brother at a neighbour’s apartment in Payson, Arizona, police said.

The semi-automatic gun that belonged to the man they were visiting was not locked up in a safe, they said. After the police dispatchers got several calls on Tuesday afternoon, alerting them to a child with a head injury, the officers rushed to find the mother carrying the wounded child to the parking lot of the apartment building. The boy was taken to Payson Regional Medical Center, where he was pronounced dead, Payson police chief Don Engler said.

“The apartment that this occurred in was a family friend of the mother and two children,” Engler was quoted by a local channel. The family had been there visiting for about 10 to 15 minutes. Engler said the children found the semiautomatic handgun in the apartment and took it to another room. He said neither adult knew the boys had the weapon.