Fredericton Police tweeted: “An incident has resulted in at least four people killed. More information will be available when we can confirm.
A second tweet shortly afterwards added: “Due to the volume of calls, please refrain from calling the police station directly, and in case of emergency continue to call 9-1-1.”
Police described it as an “active situation, urging people to “stay in their homes with doors locked at this time for their safety” and to stay away from the area of Brookside Drive between Main and Ring Road in the city, which is the capital of the New Brunswick region.
A journalist earlier reported that four shots had been heard at around 8.20am local time (12.20pm GMT).
Large numbers of emergency services vehicles are at the scene.
Robert DiDiodato, who lives on Oakland Avenue, which connects to Brookside Drive along the city’s north side, told US television network CBC he heard a series of “firecracker” sounds at about am.
He added: “With the tempo, it might’ve been a gunshot
“It was sort of like a pop, pop, pop, pop.”
(More to follow)