OAKLAND, Calif. » Oakland police handed out eviction notices at an anti-Wall Street encampment and officials elsewhere urged an end to similar gatherings as pressures against Occupy protest sites mounted in the wake of three deaths in different cities, including two by gunfire.

Police first pleaded with and then ordered Occupy Oakland protesters to leave their encampment at the City Hall plaza where a man was shot and killed Thursday.

Officers acting at the direction of Mayor Jean Quan distributed fliers to protesters late Friday afternoon warning that the camp violates the law and must be disbanded immediately. The notices warned campers they would face arrest if tents and other materials were not removed, although the warnings did not say by when.

The city issued similar written warnings before officers raided the encampment before dawn on Oct. 25 with tear gas and bean bags projectiles before arresting 85 people. A day later, Quan allowed protesters to reclaim the disbanded site and the camp has grown substantially since then.

Earlier, the Oakland Police Officer’s Association issued an open letter saying the camp is pulling officers away from crime-plagued neighborhoods.

"With last night’s homicide, in broad daylight, in the middle of rush hour, Frank Ogawa Plaza is no longer safe," the letter said. "Please leave peacefully, with your heads held high, so we can get police officers back to work fighting crime in Oakland neighborhoods."

City Council President Larry Reid said outside City Hall on Friday that the shooting was further proof the tents must come down. He was confronted by a protester who said he wouldn’t be in office much longer.

"You didn’t elect me," Reid snapped back. "You probably ain’t even registered to vote!"

The Oakland shooting occurred the same day a 35-year-old military veteran apparently shot himself to death in a tent at a Burlington, Vt., Occupy encampment.

In Vermont, police said a preliminary investigation showed the veteran fatally shot himself in the head in a tent in City Hall Park.

The death of the Chittenden County man raised questions about whether the protest would be allowed to continue, said Burlington police Deputy Chief Andi Higbee.

"Our responsibility is to keep the public safe. When there is a discharge of a firearm in a public place like this it’s good cause to be concerned, greatly concerned," Higbee said.

On Friday, a man believed to be in his 40s was found dead inside a tent at the Occupy Salt Lake City encampment, from what police said was a combination of drug use and carbon monoxide.

The discovery led police to order all protesters to leave the park where they have camped for weeks. The man has not been identified.

Group organizers said many of the roughly 150 protesters plan to go to jail rather than abandon the encampment.

"We don’t even know if this is a tragedy or just natural," protest organizer Jesse Fruhwirth said. "They’re scapegoating Occupy."

Salt Lake City police Chief Chris Burbank said officers have made 91 arrests at the camp, roughly the same number seen in the area during all of the last year.

A preliminary investigation into the Oakland shooting suggested it resulted from a fight between two groups of men at or near the encampment, police Chief Howard Jordan said. Investigators do not know if the men in the fight were associated with Occupy Oakland, he said.

Protesters said there was no connection between the shooting and the camp.

The coroner’s office said it was using fingerprints to identify the victim and that a positive identification was not likely to be released before Monday.

Protesters have been girding for another police raid as several City Council members have said the Oakland camp must go. After police cleared the camp last month, Quan changed course and allowed protesters to return.

Tensions were also high at the 300-tent encampment in Portland, Ore., which has become a hub for the city’s homeless people and addicts.

Mayor Sam Adams ordered the camp shut down by midnight Saturday, saying the tipping point came this week with the arrest of a camper on suspicion of setting off a Molotov cocktail outside an office building, as well as two non-fatal drug overdoses at the camp.

"I cannot wait for someone to die," he said. "I cannot wait for someone to use the camp as camouflage to inflict bodily harm on others."

Many at the camp said they would resist any effort to remove them.

"There will be a variety of tactics used," said organizer Adriane DeJerk, 26. "No social movement has ever been successful while being completely peaceful."

Police said some elements inside the camp may be building shields and makeshift weapons, including nails hammered into wood, while trying to gather gas masks.

"If there are anarchists, if there are weapons, if there is an intention to engage in violence and confrontation, that obviously raises our concerns," Portland police Lt. Robert King said.