‘Multiple’ people shot and suspect in custody following supermarket shooting in Buffalo, New York

(AP)

An 18-year-old man wearing military gear opened fire with a rifle at a supermarket in Buffalo, killing 10 people and wounding three others on Saturday in what authorities have described as “racially motived violent extremism”.

Police said he shot 11 black victims and two who were white before surrendering to police. Later, he appeared before a judge in a paper medical gown and was arraigned on murder charges.

The suspect wore “tactical gear” and livestreamed the shooting, according to police. He reportedly posted a manifesto online, according to the Associated Press, citing investigators who cautioned that the investigation is in a preliminary state.

The suspect arrived at the supermarket at 1430 [1830 GMT] and shot four people in the parking lot, killing three, before going into the store and firing multiple rounds.

Erie County sheriff John Garcia called the shooting “pure evil” and a “straight up racially motivated hate crime from somebody outside of our community”.

“This is the worst nightmare that any community can face,” Buffalo mayor Byron Brown said during a press conference on Saturday evening. “We are hurting and we are seething.”

The suspected shooter was not from Buffalo but “traveled hours” to “perpetrate this crime on the people of Buffalo”, according to the mayor.

The suspect dropped a rifle while standing outside the market and was tackled by police and arrested.

An employee of Tops Market who identified himself as Will G told The Buffalo News that he hid with a group of people in a supermarket walk-in cooler as gunfire rang out in the store.

“I just heard shots. Shots and shots and shots,” he told the outlet. “It sounded like things were falling over. ... I hid. I just hid. I wasn’t going to leave that room.”

The market at the intersection of Jefferson Avenue and Riley Street in Buffalo – the second-largest city in New York – is in a largely residential, predominantly black neighbourhood, roughly 5km (three miles) north of the city’s downtown area.

A statement from Tops Market said the company is “shocked and deeply saddened by this senseless act of violence and our thoughts and prayers are with the victims and their families”.

US attorney Merrick Garland has been briefed on the shooting, according to a Justice Department spokesperson.

New York governor Kathy Hochul said she is “closely monitoring” the incident and has advised residents to avoid the area.

A statement from the Erie County Sheriff’s Office offers “condolences to the family and friends” of victims. New York attorney general Letitia James said “all of New York is with Buffalo after this tragic mass shooting”.

US Rep Brian Higgins, who represents Buffalo in Congress, said he is “horrified” by reports and has offed federal support to local authorities if necessary.