ALBUQUERQUE – Hundreds of protesters marched past riot police in Albuquerque on Sunday, days after a YouTube video emerged threatening retaliation for a recent deadly police shooting.

The video, which bore the logo of the computer hacking collective Anonymous, warned of a cyberattack on city websites and called for the protest march.

Th Albuquerque Police Department said its site had been breached early Sunday afternoon, but it was visible late in the afternoon after being offline for hours.

The site was not “connected to any critical services,” police spokesman Simon Drobik said.

Demonstrators, meanwhile, arrived at Civic Plaza holding signs protesting recent police shootings, and activists called on various city officials to resign.

The protest began Sunday afternoon and continued into the early evening as demonstrators marched around the city.

By about 6 p.m., a few hundred demonstrators had gathered downtown near police headquarters where they confronted about three dozen officers in riot gear.

Authorities announced over a loudspeaker the protest was an unlawful assembly. Demonstrators, meanwhile, chanted, “No justice, no peace!”

Albuquerque police have been involved in 37 shootings, 23 of them fatal since 2010. Critics say that’s far too many for a department serving a city of about 555,000.

The U.S. Justice Department has been investigating the department for more than a year, looking into complaints of civil-rights violations and allegations of excessive use of force.

Last week, Albuquerque police fatally shot a man at a public housing complex. Authorities said he shot at officers before they returned fire.

In the shooting March 16 that led to the YouTube posting Tuesday, a homeless man was killed in the foothills of the Sandia Mountains on the east side of Albuquerque. The shooting was captured on a polic lapel video and followed a long standoff.

Anonymous, a loosely organized worldwide hacking group, has been blamed for breaking into confidential information and defacing websites.

The FBI has opened an investigation into the shooting.