Four people were shot dead in the city of Philadelphia late on Monday, US police have said.
They said another two – children aged two and 13 – were injured in the attack in the city’s south-western Kingsessing area. All the victims are male.
The suspected gunman is now in custody and his rifle and handgun have been recovered.
Police added that the suspect, who has not been named, was wearing a ballistic vest with “multiple magazines”.
At a news conference, Philadelphia Police Commissioner Danielle Outlaw said officers were flagged down at about 20:30 local time on Monday (01:30 BST Tuesday) in the area of 56th Street and Chester Avenue.
“When officers responded, they did identify and find some gunshot victims. As they were scooping up the victims and preparing them for transport to hospital, they also heard multiple gunshots,” she said.
The commissioner added that the officers then pursued the suspect on foot while the man – believed to be 40 years old – was “actively shooting”. He was later detained.
Three of the killed men were aged between 20 and 59, while Ms Outlaw said the fourth could be aged between 16 and 21. The two injured children are in a stable condition.
Ms Outlaw added there could have been more victims, had it not been for the officers’ actions.
The suspect’s motives were not immediately known.
Another person has also been held by police. That person is believed to have “acquired a gun somehow… and returned fire in the direction of the shooter,” the commissioner said.
The attack on the eve of Independence Day came just a day after two people died and 28 were injured – about half of them children – in a shooting attack in Baltimore, Maryland.
Authorities there are still searching for multiple suspects who are believed to have opened fire during an annual community gathering.
At least four people have been killed in a mass shooting at a 16th birthday party in the US state of Alabama.
Twenty-eight people were injured, some critically, after shots were fired at the Mahogany Masterpiece Dance Studio in the city of Dadeville on Saturday.
High school senior Phil Dowdell, a star athlete, has been named by local media as one of the victims.
President Joe Biden renewed his calls for tougher gun laws after the incident.
“What has our nation come to when children cannot attend a birthday party without fear?” Mr Biden asked, in a statement released by the White House on Sunday.
This shooting takes the US to a grim milestone of more than 160 mass shootings – in which four or more people are shot – so far this year, according to the Gun Violence Archive.
With a population of about 3,200 people, Dadeville is a small, rural city which is not used to scenes of violence on this scale.
What is striking right now, and unusual, is how little we know about a possible suspect.
Next to no details have emerged about how the shooting was brought to an end, or whether a suspect has themselves died or is in custody.
Sgt Jeremy Burkett of the state’s law enforcement agency said the investigation would be a “long, complicated process”.
“We’re going to work in a methodical way to go through this scene, to look at the facts and ensure that justice is brought to bear for the families,” he said late on Sunday.
The injuries ranged from “extremely critical” to minor, he said.
It is likely that most of the victims were teenagers. Some of the parents were still searching for information about their children 12 hours after the shooting took place.
Among those who are known to have been killed is Phil Dowdell, who was named by his grandmother in local media.
He was a senior in high school and was going to Jacksonville State University on an American football scholarship.
Pastor Ben Hayes, who serves as chaplain for the Dadeville Police Department and for the local high school football team, said: “One of the young men that was killed was one of our star athletes and just a great guy.
“I knew many of these students. Dadeville is a small town and this is going to affect everybody in this area.”
At a local parking lot where a vigil was being held, teenagers could be seen visibly shaking and crying from the shock of what happened last night.
Many shared hugs and tears as they tried to comfort one another.
One woman at the vigil, Shondra, told the BBC her cousin was at the birthday party last night. “They were being free, they were celebrating a life,” she said.
“You never think it’s going to happen in your area.”
Keenan Cooper, the DJ at the birthday party in the dance studio, told reporters he tried to help get guests under tables when it started, but it was too dark to see where and who the shots were coming from.
He said the party was for Phil Dowdell’s sister, as earlier reported by local outlet the Montgomery Advertiser.
The area around the dance studio remains cordoned off.
As the town woke to the news on Sunday, Alabama’s state governor Kay Ivey said: “This morning, I grieve with the people of Dadeville and my fellow Alabamians.
“Violent crime has no place in our state, and we are staying closely updated by law enforcement as details emerge,” the governor added in a statement on Twitter.
Alabama is a state known for protecting the right of citizens to own guns, and the Republican governor’s message of condolence has been met with criticism on social media by those advocating for gun law reform.
Ivey is a strong supporter of second amendment rights – the right to keep and bear arms – and last year signed legislation ending a requirement to obtain a permit to carry a concealed handgun in public.
Her candidacy for last year’s governor election was endorsed by the National Rifle Association.
The incident in Tallapoosa County, in the east of Alabama, follows a shooting on the same day at a park in Louisville, Kentucky, which killed two people and injured four others. In his own statement, Mr Biden said the nation was “once again grieving” and described the rise in shootings as “outrageous and unacceptable”. He said the American people wanted lawmakers to act on “common sense gun safety reforms”.
A man armed with three guns fatally shot his ex-wife and five others during a rampage in a small rural town in the US state of Mississippi, police say.
The victims were killed at several locations, including a store and two homes, in Arkabutla, a community of fewer than 300 people.
Police have charged a 52-year-old local man with first-degree murder and held him at the county jail.
No motive for his attack has yet been identified.
The suspect is believed to have acted alone, said Mississippi Governor Tate Reeves.
The rampage began when the gunman entered a petrol station convenience store at around 11:00 local time (17:00 GMT) and shot a man to whom he had no apparent connection, Sheriff Brad Lance said.
He then went to a nearby home where he fatally shot his ex-wife and, according to CNN, struck but did not shoot her fiance.
Investigators say the gunman then drove to a home next to his own residence and fatally shot a man who may have been his stepfather, as well as an unnamed woman, the New York Times reports.
He then shot two people, one inside a car and one on the road, not far from his own home. The final two victims appear to have been construction workers on a job at the site, according to Sheriff Lance.
Deputies spotted the suspect inside a vehicle matching witness descriptions and were able to apprehend him near his home after a brief car chase.
“We don’t have a lot of violent crime here. This is shocking,” said Sheriff Lance. “I never dreamt that we would deal with something like that here.”
He said the suspect had a shotgun and two handguns in his possession.
A primary and secondary school in nearby Coldwater were placed on lockdown during the incident, which unfolded 45 miles (72km) south of Memphis, in neighbouring Tennessee.
Ethan Cash, a 19-year-old local resident, told WREG-TV that he had seen the gun-toting suspect.
Mr Cash said he also checked the pulse of the victim who died inside his vehicle and drew his own pistol on an injured man nearby who turned out to be the victim’s brother.
Friday’s incident marks the 73rd mass shooting since the year began, according to the Gun Violence Archive (GVA) non-profit research database.
GVA defines a mass shooting as an incident in which four or more people are injured or killed.
No suspects have been arrested over Saturday’s shooting and no motive has been identified.
Mr Simmons said the two victims, a man and a woman who have not been named, were aged between 18 and 22. None of the 14 others who were shot suffered life-threatening injuries.
“This is yet another tragedy where individuals are having these illegal, unsanctioned house parties taking place in these properties, which number one is not safe because of Covid,” said Mr Simmons.
“And then you add in alcohol and violence and it just becomes a recipe for disaster.”
