WESTPORT — After a call came in Tuesday morning about a suspicious package in town, fire officials are urging residents to be vigilant when they notice something strange.

Shortly after 9:30 a.m., fire units were called to a home to help Westport police investigate a call about a suspicious package, said Deputy Fire Chief Michael Kronick.

The department sent seven firefighters to the scene. Three of the seven firefighters are Hazardous Materials Response Technicians.

“These firefighters are trained in responding to incidents that may involve hazardous materials,” Kronick said. “They were able to properly identify the material in question as non-hazardous.”

Kronick warns that suspicious packages can be any size and shape. Suspicious packages can be anything from a box, bag, backpack or other item that is left unattended or that seems out of place.

“The Westport Fire Department would like to remind our residents that if you see or suspect that you have received a suspicious package, immediately call 911 to report it,” Kronick said.

Suspicious packages and mail typically include misspelled words or will arrive unexpectedly. There might be restrictive markings on it, including a notice that it’s “personal” or “confidential” — it could also say “do not X-ray.”

A suspicious package likely will have a postmark that doesn’t match the return address. Sometimes there will be no return address, Kronick said. There can be excessive postage, or a wrong title or name in the address.

If there is excessive tape or string, if the package is rigid or bulky, call 911 and report the suspicious package, Kronick said.

More indicators of suspicious packages can include protruding wires, crystals or a powder-like residue, strange odor, ticking sounds, and oily stains or discolorations on the wrapping.

But any resident who receives a suspicious package would do well to stay calm and not open it, Kronick said.

“Do not shake it, do not show it to others, or empty its content,” he said. “Leave the letter or package where it is or gently place it on the nearest flat surface.”

After that, the immediate next step is always to call 911. Kronick said it’s best to alert others nearby to relocate to an area away from the site of the package.

“Leave and close the door to the space containing the suspicious letter or package,” Kronick said. “Keep others away.”