BATON ROUGE, LA -- Calling it a "substantial, credible threat" to police, authorities in Louisiana have arrested three suspects accused of stealing at least eight handguns in an alleged plot to harm police officers in the Baton Rouge area.The arrests in Louisiana's capital city come amid heightened tensions following the deadly police shootings of black men in Baton Rouge and Minnesota and the killings of five police officers in Dallas last week.Authorities discovered the alleged plot while responding to a weekend burglary at a pawn shop, Baton Rouge Police Chief Carl Dabadie said at a news conference Tuesday.The chief said the first suspect arrested told police that "the reason the burglary was being done was to harm police officers." He said the suspect didn't give any details about when or where a possible plot would be carried out.State Police Col. Mike Edmonson called it a "substantial credible threat" to police.All of the suspects are from Baton Rouge and all are black. They face charges including burglary, simple burglary, and theft of a firearm; they have not been arrested on any charges related to plotting to kill police.Six of the eight stolen firearms have been recovered and two are still at large, authorities said."We have been questioned repeatedly over the last several days about our show of force and why we have the tactics that we have. Well, this is the reason, because we had credible threats against the lives of law enforcement in this city," Dabadie said.In a statement, police said surveillance video showed the suspects using a ladder to climb the roof of the building to get in early Saturday. Eight handguns and one airsoft BB gun were missing from the store.Authorities said they arrested one suspect - Antonio Thomas, 17 - at the scene with a handgun and a BB gun. Another suspect, Malik Bridgewater, 20, was apprehended Sunday and a third suspect - a 13-year-old boy - was apprehended on a street. They called on a fourth suspect to turn himself in. Another man was arrested for allegedly purchasing two of the stolen guns, but he hasn't been linked to the alleged plot, a police spokesman said.It wasn't immediately known if those arrested had attorneys.In the first few days after 37-year-old Alton Sterling was shot and killed after being pinned down by two white police officers in Baton Rouge, police took a reserved approach to enforcement, keeping a low profile as hundreds gathered outside the convenience store where Sterling died.But tensions escalated during weekend protests that moved away from the store and into other parts of the city, marked by a show of force by law enforcement that included police wielding batons, carrying long guns and wearing shields. Over a three-day period, police arrested about 200 protesters and came under criticism for the tactics used to deal with the demonstrations.Earlier Tuesday, Louisiana Gov. John Bel Edwards defended the police response. He said the riot gear and weaponry were appropriate."We've had a police officer with teeth knocked out of his face because of a rock. If you don't have on riot gear, you have no defense against that sort of thing," the Democratic governor said."In light of what happened in Dallas, understanding that just one gunman can change the situation entirely, how do you in good conscience put police officers on the street without the ability to defend themselves?" he added.Protests have spread around the country as people expressed outrage over the recent death in Baton Rouge and of a second black man, Philando Castile, at the hands of police in Minnesota last week. The Justice Department has opened a federal civil rights investigation into Sterling's shooting.Community leaders in Baton Rouge have sought to defuse the tension.State Rep. Ted James, a black lawyer who grew up near where Sterling was shot, and Cleve Dunn Jr., a prominent black businessman, met with local Republican leaders at a public luncheon to discuss the shooting. The two also have showed up at protests, urging calm."I truly believe that we can have parallel conversations about respect for police officers, making sure that they're safe, but also have a parallel conversation about the things that are happening with African-American males across the country," James said.