A man killed his daughter and six grandchildren, the youngest just three months old, in a mass shooting at a house in the US state of Florida on Thursday.
The shooter, identified as Don Charles Spirit, 51, then killed himself, said Gilchrist county sheriff Robert Schultz.
The oldest child was age 11.
Officials work on NW 29th Terrace near the scene of the shooting on Thursday in Florida. (AP Photo)
"I haven't seen anything like this at all," Schultz, who was visibly shaken, told reporters.
"This county, this community is going to be devastated from this. It is a small county, we are all family here.
"We're asking for prayers for this community and the families involved."
Spirit had contacted emergency services saying that he was considering harming himself and others, but when police arrived at the home in the small town of Bell, his daughter and young grandchildren were all dead, police said.
Spirit reportedly killed himself while police were there.
In an incident later ruled an accident, Spirit shot and killed his nine-year-old son during a 2001 hunting trip, the Tampa Bay Times reported.
The child died instantly from a bullet wound to the head, caused by Spirit's rifle going off while he cleaned rust from the barrel, the paper said.
Thursday's grisly episode is sure to revive passionate debate about gun ownership in the United States, where 11,000 people were murdered by gun violence in 2011, according to FBI figures.
A Gilchrist County sheriff's deputy lowers the yellow tape to let vehicles through at the scene of the shooting on Thursday in Florida. (AP Photo)
However firearms-control activists face fierce opposition from America's powerful pro-gun lobby, which staunchly opposes any effort to limit any restriction of the second amendment of the US Constitution, which protects citizens' rights to own guns.
US President Barack Obama tried and failed to introduce a ban on assault weapons and to require more stringent background checks for gun buyers after the Newtown massacre in which 20 children and six adults were killed in December 2012.
The measures foundered against the strong support for gun rights in the US Congress and the power of the firearms lobby.
The National Rifle Association and other gun groups then mounted a successful counter-campaign, warning members that the US government was bent on taking guns away.
US school shootings have become a periodic tragic occurrence in recent years, generally generating public debate on gun control in their aftermath.
The topic was once again in the US news last month, when a nine-year-old girl learning to fire an Uzi submachine gun accidentally killed her instructor when she lost control of the powerful weapon.