Two teens arrested in Virginia last week and accused of fatally shooting bystanders during the mass shooting on South Street earlier this month were extradited to Philadelphia Wednesday and were expected to be arraigned on murder charges, officials said.

Qaadir Dukes-Hill, 18, and Nahjee Whittington, 18, had been taken into custody last Thursday by U.S. Marshals in Richmond, Va. Philadelphia authorities said the teens, who are friends, each fired shots randomly into a frightened crowd packing the nightlife district on June 4 after a brawl and gun battle erupted a block away.

» READ MORE: How the South Street shooting unfolded, minute by minute

The entire incident — which spanned several blocks and included five gunmen — left three people dead and 11 wounded, police said, and the teens are expected to be charged with causing two of those deaths. Dukes-Hill is accused of fatally shooting 24-year-old Alexis Quinn, a home health aide, while Whittington is accused of fatally shooting Kristopher Minners, a residential adviser at Girard College who was celebrating his 22nd birthday.

Whittington is also expected to be charged with shooting another man in the calf, officials said, and both he and Dukes-Hill could face additional charges if ballistics tests show their bullets struck other victims.

The shooting — a chaotic episode that spanned more than a block — claimed more victims than any single episode of gun violence in Philadelphia in at least seven years. And it came in the wake of other mass shootings across the country, including in Buffalo, N.Y., and Uvalde, Texas.

» READ MORE: South Street shooting victim Alexis Quinn remembered as a loyal, loving daughter who ‘brought people together’

The incident on South Street was sparked by a fistfight. Prosecutors have said when two groups of men encountered one another on the 200 block of South Street around 11:30 p.m., a brawl quickly devolved into a gun battle, with one of the participants — Gregory Jackson, 34 — firing at another, 23-year-old Micah Towns.

Towns was struck in the body, prosecutors said, but fired back at Jackson, killing him. Officials said it was not clear why the fight began.

Moments later and across the street, prosecutors said, 18-year-old Quran Garner — an apparent friend of Towns’ — began firing shots from a homemade “ghost” gun into the panicked crowd. A police officer who arrived noticed Garner shooting and returned fire, prosecutors said, striking Garner in the hand and causing him to run away.

» READ MORE: Kristopher Minners, killed in the South Street shooting, was celebrating his 22nd birthday

As the chaos escalated, Dukes-Hill and Whittington — who were standing in different spots a block away, on the 300 block of South Street — pulled their guns and began randomly firing toward the initial fight, prosecutors said. Officials do not believe the teens knew anyone involved in the brawl, but said their wayward shots fatally struck Quinn and Minners and wounded at least one other bystander.

Garner, the teen who allegedly fired the ghost gun, was arrested last week and arraigned on counts including aggravated assault and weapons offenses. Another man, Rashaan Vereen, 34, accused of participating in the initial brawl with Towns, is charged with crimes including attempted murder.

Prosecutors said Towns, who fatally shot Jackson in the fight, had fired in self-defense and was unlikely to face charges.

Dukes-Hill and Whittington were being processed Wednesday evening, police officials said. It was not immediately clear when they might be arraigned, but they are expected to face charges including murder and weapons violations.