CHARLOTTE, N.C. -- A fourth package explosion in Austin, Texas in less than three weeks is leaving people across the country on edge.
Officials said these explosions appear to be the work of a serial bomber.
The explosions started March 2, with the latest happening Sunday night in a southwest Austin neighborhood.
Two people have died and four others have been seriously injured in the attacks.
Austin Police Chief Brian Manley said, “If you see any suspicious object or item that looks out of place, do not even approach it, but instead call 911 and report that to the police department.”
The explosions are even causing fear in the Queen City.
“It’s very concerning to just have innocent people being harmed by just simply receiving some kind of random package,” said Julia Montgomery, an uptown Charlotte resident.
The first three explosions were caused by package bombs left near homes in Austin.
Mailing companies offer tips to verify that deliveries are legitimate.
UPS says their drivers are in uniforms and marked trucks and will knock on the door. It also has a free program to keep you posted for delivery updates.
The United States Postal Service (USPS) says it does contract out deliveries, but carriers should be wearing something with a USPS label and driving a marked car. You can also always check a package's status by tracking it.
Officer Johnathan Frisk with CMPD crime prevention said, "if you did not order the package or you don't have anything being delivered [or] if it's coming from Amazon or whoever it's coming from -- obviously there's no reason to pick that package up."
Officials recommend always checking the return address and standing away from the package if you don’t recognize the sender. Frisk said to contact the carrier service to verify the package, and if necessary, alert authorities.
"Just being aware of, you know, the packages and everything else coming in your mailbox will help keep people safe,” Frisk said.
The fourth explosion Sunday night in Austin is shifting the safety message and making it even broader since the device was not found on a front porch. Officials say people need to be on the lookout for anything that might be a suspicious device, including packages, bags, or backpacks.