At least eight Walmart locations have received threats over the past week after deadly shootings at two stores in recent weeks, law enforcement agencies said.
The threats follow a horrific massacre at a Walmart in Texas last weekend and a deadly shooting at a store in Mississippi late last month.
In Florida, Richard D. Clayton, 26, was arrested after he allegedly posted a threat on Facebook that he was about to have his gun returned and people should stay away from Walmart.
He was detained Friday after an investigation by various agencies, including the FBI, the Winter Park Police Department and the Florida Department of Law Enforcement.
He allegedly made a threat Tuesday on a Facebook post stating, "3 more days of probation left then I get my AR-15 back. Don't go to Walmart next week," the Florida Department of Law Enforcement said.
He remains in custody on $15,000 bond, according to online records . It is unclear whether he has an attorney.
In other incidents:
• On August 4, a Florida man from the Tampa area called a Walmart and told an employee he would shoot up the store, the Hillsborough County Sheriff's Office said in a statement. The man faces a false threat charge.
• In Texas, officers responded to a threat posted Saturday on social media, the Harlingen Police Department said in a statement . "During the course of this investigation, officers learned that a male subject had used a social media site to post up an imminent threat that was to occur at the Walmart in Harlingen on a specific date," it said. A man was arrested at his home for making a terroristic threat and is awaiting arraignment.
• Also in Texas, police in Weslaco arrested a 13-year-old boy after the boy's mother brought him to the station Saturday. The boy will face a charge of terroristic threat for making a social media post Wednesday that prompted a Walmart to be evacuated, police said on Facebook .
• In Springfield, Missouri, a man was arrested Thursday after panic ensued when he walked into a Walmart equipped with body armor, a handgun and a rifle. He faces a charge of making a terrorist threat in the second degree, the police department said on Twitter.
"I wanted to know if Walmart honored the Second Amendment," Dmitriy Andreychenko told investigators, according to a probable cause statement filed by Springfield police. CNN was unable to determine whether he was represented by an attorney.
Walmart spokesman Lorenzo Lopez said the chain is focused on safety and security at its 5,000 US stores.
"We take threats seriously and provide additional security as appropriate. We will continue to help federal and local authorities with their investigations to determine the source and any credibility of the threats." he said.
• An anonymous source reported a person with a gun at a New York Walmart on Saturday, according to the Cortland Sheriff's Office. Officers responded but did not find anyone armed.
• Multiple 911 calls reported a man with a gun in a Walmart in North Carolina, an open carry state, Wilkesboro Police Capt. Jason Delbert told CNN. A man was detained and is being questioned, police said. It is unclear if the man was menacing anyone with the gun.