Nassau County Executive Edward Mangano on Sunday issued a warning to those targeting and gunning down police officers.

“Target our citizens, target our police, and you’re going home in a body bag,” Mangano said to thunderous applause at Eisenhower Park in East Meadow, where hundreds of firefighters representing every Nassau fire department and some from Suffolk County rallied in support of police.

July has seen an uptick in police shootings nationwide. Earlier this month, Gavin Long, 29, of Kansas City, Missouri, shot and killed two police officers and a sheriff’s deputy and injured three others in Baton Rouge, Louisiana.

Also this month, Micah Xavier Johnson, 25, of Mesquite, Texas, ambushed and killed five officers, shooting nine others as a Black Lives Matter demonstration was ending in Dallas.

“So now we’ve come to a time where cowardly terrorists are now targeting our own police officers, the keepers of peace,” Mangano said to the crowd. “But we’re here to say we have our police’s back.”

Republican state Sen. Jack Martins echoed Mangano’s stance toward those who target police officers.

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“Our police department is literally the difference between life and death,” Martins said. “[If] you take on the police, you take on society; you’re going home in a body bag.”

During the rally, the fire departments saluted a large number of officers under an American flag.

“We’re basically saying thank you to the cops,” said Uniondale Fire Chief Jean Laurent. “In Long Island, we work together.”

However, East Meadow resident Neil Khosla said America is increasingly divisive.

“Right now, people are saying it’s us versus them,” Khosla, 21, said, adding there is a misconception that people who support the Black Lives Matter movement don’t support all lives. “What a black person goes through in America is different from other Americans.”

Stewart Manor Fire Department First Deputy Chief Thomas Skinner spearheaded Sunday’s rally.

“I was watching the assassination of police officers [on television] in Baton Rouge and was going to put something into action,” he said.

Tom Fitzsimons, former Baldwin fire chief, said he was taken aback by the shootings as they unfolded.

“To randomly shoot officers is terrible,” he said. “It’s unnecessary. There should be more support for the police.”