JEFFERSON CITY, Mo. -- Jefferson City police said a security officer inside the Governor Office Building overheard through an elevator intercom about a possible hostage situation. The officer notified her supervisor who then called security.

It turns out there was no hostage situation, but it led to an anxious day in downtown Jefferson City on Tuesday.

As soon as word broke of the possibility of the hostage situation officers wasted no time locking down the building and the 200-plus workers who were inside.

Mike Parnell works inside the building and he was showing a client to the door when the building went on lockdown.

"He thought he could go out the back door and into the lobby and when he opened the door there were officers there with rifles pointed waiting for him," he said.

"At this point I'm not calling it anything," Capt. Mike Smith of the Jefferson City Police Department told a 4 p.m. news conference. "Our investigation might reveal that this was a hoax, but at this time we just don't know yet."

Officials removed the barricades from outside the Governor Office Building by mid-afternoon where a possible hostage situation was reported on Tuesday morning.

The office building was the site of an extraordinary law enforcement response has been cleared and whatever might have sparked the response -- including SWAT teams, a helicopter and snipers -- has ended.

KRCG in Jefferson City reported late Tuesday morning that police have shut down a city block because of a possible hostage situation at a downtown office building.

Jefferson City Police said they received an alarm message about a hostage situation, but they said they have not been able to confirm it.

THe St. Louis Post-Dispatch reported that Capt. Tim Hull, of the highway patrol, said a woman in the building thought she heard the word “hostage” over an intercom. She called the building’s security company, which contacted police. Authorities locked the building down and continue to investigate.

Jefferson City Police along with Capitol Police, Highway Patrol, and the Sheriff's Department surrounded the Governor Office Building at 200 Madison St.

A person on the fifth floor of the building reported that it was a hostage situation.

On Tuesday morning, KRCG reported that hostage negotiators were on scene in Jefferson City after police received an alarm of a hostage situation.

The Governor Office Building primarily houses the staff of the Missouri Public Service Commission, which regulates utilities. It also is home to the state's consumer advocacy office and a development finance board.

State employees in the building, reached by phone by The Associated Press, said police have told them to remain in their offices with the doors locked.

Gov. Jay Nixon flew back to town from Texas when he heard about the possible situation.