Updated

While hundreds of demonstrators battled tear gas during a downtown demonstration against an alleged pattern of lethal force by the Albuquerque Police Department, the hacker activists known as Anonymous were apparently registering their protest with a cyber attack on the department's website.

Albuquerque officials say the city experienced a "temporary, brief disruption" over the weekend to the city website.

"The cyber attack was successful," said Albuquerque Mayor Richard Berry.

The sophisticated attack, which began late Saturday night and extended through Sunday was triggered a denial of service due to what officials said was a well-coordinated activity.

"It's hard to prevent these attacks," said Peter Ambs, chief information officer for the city. "If someone tells you a hurricane is coming you can prepare for it but not prevent it."

While officials acknowledged the successful attack, they were reluctant to conclude it was linked to threats made earlier in the week by Anonymous, which threatened a cyber attack on the department's website in response to the March 16 shooting death of a mentally ill homeless man at the base of the Sandia Mountains.

A second man, Alfred Redwine, was shot and killed by police nine days later. These incidents brought the total of people shot by police to 37 since 2010, 23 of which were fatal.

The Boyd incident is being investigated by the FBI. The Department of Justice has an ongoing investigation into the lethal force incidents of the APD. Last year the Police Executive Research Forum conducted a study of the department's policies and made recommendations to outgoing Chief of Police Ray Schultz.

"Anonymous, grab your cannons and point them at Albuquerque police websites," said the Internet threat that called for activists to flood the Albuquerque Police department website.

Ambs said this is the biggest disruption of service the city has experienced.

"Periodically we do get denial of service attacks, but nothing this large," he said.

The police department website experienced multiple shutdowns lasting as long as 30 minutes.

"This was a particularly highly concentrated effort," Ambs said. "We can't confirm the source at this time."

The cyber attack-demonstration was part of a larger street demonstration that brought more than 400 demonstrators to a march from the Albuquerque Police headquarters east along Central Avenue to the fringe of the University of New Mexico campus where police eventually were required to use tear gas to disperse the increasingly unruly crowd.

Berry said there was extensive graffiti and vandalism committed. Some demonstrators attempted to block traffic on the bust Interstate 25 which bisects Albuquerque.

"We had crews out cleaning up the graffiti early Monday," Berry said.