Suspect James Yoo believed killed in Virginia house explosion

A man is presumed dead after his house in a suburb of Washington DC exploded during a standoff with police.

Authorities said James Yoo, 56, was the sole occupant of his unit in a duplex house in Arlington, Virginia.

Officers were called to the house at 16:45 local time (21:45 GMT) on Monday after reports of someone firing a flare gun.

Neighbours were evacuated. When police approached the building, shots were fired, and the house exploded.

Three officers sustained minor injuries, but police said on Tuesday that no neighbours or bystanders were hurt.

Around 10 to 12 homes in the surrounding area were affected by the blast. Police are still investigating what caused the explosion.

Fire officials said the gas supply to the house had been turned off prior to the blast.

The incident began when police say Mr Yoo fired a flare gun more than 30 times from inside his home.

After authorities were called, they got a search warrant for the home.

They first tried to speak to Mr Yoo over the phone and through loudspeakers, but he did not respond.

Arlington County Police Chief Andy Penn said officers then broke down the door to the home and came under suspected gunfire.

"Officers could not locate the source of the suspected gunfire or its intended target," Mr Penn said during a news conference on Tuesday afternoon.

Police used what they described as "non-flammable" chemicals in areas where the suspect was believed to be hiding in an attempt to get him out of the home.

The house blew up shortly afterwards, at around 20:25.

Human remains were found in the wreckage and medical examiners are working to positively identify them as those of the suspect, Mr Penn said.

There is no ongoing threat to the public and no other suspects, police said.

Years of lawsuits

Mr Yoo's social media accounts indicated that he spent years filing legal claims and alleging conspiracies with little evidence to back them up.

He posted videos online of documents from a number of lawsuits that accused people of stalking, threatening and harassing him.

Mr Yoo's claims were consistently thrown out by the courts.

Police are also looking into "concerning social media posts" believed made by Mr Yoo.

Mr Penn said that Arlington Police had not encountered Mr Yoo with the exception of two noise complaints "over the past couple years".

Dave Sundberg, assistant director of the FBI's Washington field office, said that Mr Yoo had contacted the bureau several times over the years making allegations of fraud, but none of the messages resulted in any investigations.

The blast shook surrounding buildings, and authorities are assisting several families who could not yet return to their homes.

Videos circulating on social media showed debris and plumes of smoke flying into the air as the house explodes, blasting off the roof of the house and crumbling its walls.