Police in Oklahoma have arrested two white male suspects over shootings that left three people dead and two more critically wounded, all black, in the Tulsa area.
The Friday morning shootings left the city's black community on edge throughout the weekend.
Authorities had said they thought the shootings in a predominantly black neighbourhood by an attacker or attackers were linked because they happened at around the same time and all five victims were out walking when they were shot.
Tulsa police spokesman Jason Willingham said the two men were arrested at a house just north of Tulsa at 1.47am local time and were expected to face three charges of first-degree murder and two counts of shooting with intent to kill.
Mr Willingham said: "There obviously still is a lot of investigation ahead. We don't have a motive at this time. We are still asking questions and hopefully that will become clear in coming days."
Mr Willingham identified the men in custody as 19-year-old Jake England and 32-year-old Alvin Watts, but gave no addresses. He said they were taken in early today for questioning at a Tulsa police station.
He said authorities still faced many unanswered questions after the arrests.
"We are going to turn over every rock," he said of the investigation.
Police had said previously that they were searching for a white man driving a white pick-up, which was spotted in the area where three shootings took place. At least two dozen officers were called to investigate the case, along with the FBI and US Marshals Service.
He said the arrests followed an anonymous tip-off received on Saturday, but he declined to specify what that tip-off was. Mr Willingham said he did not have any immediate details when asked if the men were armed when they were arrested.