CLEVELAND - What began just a week ago with a spur-of-the-moment Facebook page turned into an impressive demonstration of support for police in downtown Cleveland on Saturday as several thousand people turned out for a "Sea of Blue" rally.

Mary Jo Graves, a police dispatcher in a Cleveland suburb, had hoped that 100 people might join her when she created the page. She said after Saturday's event that she was overwhelmed with the turnout and hoped other cities would hold rallies on behalf of police.

Graves began the rally on Public Square by telling the crowd about how dangerous officers' jobs are and how their families are affected.

"They go out every day to protect us, whether they know us or not," Graves said. "They don't put their uniforms on and go out and plan to kill somebody. They pray that they're going to come home."

Many in the crowd wore blue as Graves had asked on her Facebook page. Some carried signs that said: "Blue Lives Matter."

Cleveland has seen a number of anti-police protests in recent weeks, some prompted by the Nov. 21 fatal shooting of 12-year-old Tamir Rice, who was holding a pellet gun when a police officer responded to a report of a man with a gun.

Saturday's crowd marched in virtual silence to a police memorial park several blocks away. They were asked to remain silent to honor one of the recently slain New York City police officers, whose funeral was Saturday afternoon.

Before the rally, former Berkeley, Calif., police officer Chris Samuels, who grew up in Cleveland and returned when he retired, said the "social media age" is partly responsible for the current atmosphere of antagonism toward police officers.

"Everything's out there in a matter of seconds, which would be all right if everything said was true," Samuels said.

Outside police headquarters, two Cleveland police officers stood and watched the crowd pass by. They said they were heartened by the support. One said police are good people who are just trying to help others when they do their jobs.

Flags flew at half-staff at the memorial, where relatives and loved ones of fallen police officers spoke.

One of those speakers was Tiffany Miller, the fiancee of Akron police Officer Justin Winebrenner, who was shot and killed last month when he tried to push an unruly and armed customer out of a bar. Miller watched the customer shoot Winebrenner, who was off-duty, she said.

"I was next to him and he saved my life along with many others on that dreadful night," she said.

Miller said she feels many emotions, including anger, toward the man who killed Winebrenner.

She then added, "I feel sadness that I will not see his face down the aisle on our wedding day in June."

Across the street from the memorial park, a group of about 30 people gathered on the steps of the Cuyahoga County Justice Center, some holding signs in support of Tamir. A line of police motorcycles separated the group from those attending the rally; there were no confrontations between the two sides.

The pro-police rally ended with a priest leading the crowd in a recitation of "The Lord's Prayer," followed by the mournful skirl of a bagpipe. The crowd then walked away in silence.