A security guard accused of killing his sister, her husband and six others had a history of mental problems and feared his sister wanted to kick him out of the home they shared, relatives and others said.

Bomb squad police were detonating a huge explosives haul today at the home of a man accused of shooting dead eight people in Virginia's worst mass killing incident since 2007.

A gunman wanted for murdering eight people in a house then firing at a police helicopter surrendered today after a huge manhunt.

A massive manhunt involving more than 100 police and helicopters with thermal imaging was under way today for a gunman who killed eight people in Virginia.