(Adds quote from mayor, more on attack on police website)
By Joseph Kolb
ALBUQUERQUE, March 31 (Reuters) - New Mexico's governor urged calm on Monday after weekend protests over the police shooting of a mentally ill homeless man in Albuquerque turned to scuffles and ended with shots of tear gas into the crowd.
Four people were charged with disorderly conduct as a result of Sunday's melee, during which the online activist hacker group Anonymous was suspected of also disrupting the police department's website, city spokeswoman Breanna Anderson said.
Sunday's scuffles followed a rally to protest what critics call excessive use of lethal force by the Albuquerque police, an issue the U.S. Department of Justice has been investigating since 2012.
Protesters ended up throwing stones at the police after a rally triggered by the March 16 killing by Albuquerque police of a homeless man named James Boyd. Mounted police and others in riot gear confronted demonstrators near the University of New Mexico, using tear gas when they refused to disperse.
"Albuquerque is going through a tough time, and they'll figure it out through the investigation," Republican Governor Susana Martinez said on Monday. "We want that to be thorough. We want confidence in the investigation, but I just don't want to see anyone harmed."
Some 37 people have been shot by Albuquerque police since 2010, 23 of them fatally, a police spokeswoman said. Protesters contend that is too high for a city of just over half a million people.
Albuquerque Mayor Richard Berry said he did not blame the organizers for the violent turn that the event took, adding that several law enforcement agencies, including the FBI, were investigating the shooting that sparked the protest.
"It appears those who started the protest weren't intent on breaking the law, but it got away from them," Berry said, adding that about 300 to 400 protesters took part in the demonstrations.
One police officer suffered a minor knee injury that was not caused by the protesters' actions, Anderson said. The crowd finally dispersed around midnight.
Peter Ambs, the city's chief information technology officer, said the police website was subjected to a so-called denial of service attack, in which hackers bombard websites with requests causing them to slow or crash.
He said the attack started at 10 p.m. local time on Saturday and lasted through the end of the protest on Sunday night.
While city officials have said they believe Anonymous, whose members threatened the site last week, was to blame, Ambs said the police department was still investigating the hacking.
Although the site is functioning, "it's going to take our staff a period of time to fix certain things," he said. (Additional reporting by Chris Michaud in New York and Sharon Bernstein in Sacramento; Editing by Mark Heinrich, Lisa Shumaker and Richard Chang)