MIAMI BEACH, Fla. -- Miami Beach police remain in a standoff in an effort to locate two people who they believe were part of a robbery at a bank, which may have turned into a hostage situation across the street.

Meanwhile, two schools remain on lockdown and parents are being advised to not go to the schools to pick up their children until the lockdown is lifted, according to police.

Nautilus Middle School, 4301 N. Michigan Ave., and North Beach Elementary School, 4100 Prarie Ave., remain on lockdown, police said. Children who take buses home will still be transported on buses when the lockdown is lifted, police said.

Miami Beach police spokesman Bobby Hernandez said officers responded to a robbery-in-progress call Tuesday morning at the Commercial Bank of Florida and took one man into custody.

At that time, Hernandez said, police received phone calls at the bank from someone threatening to open fire if the man was not released.

"Subsequent to that phone call, people start running out of the building across the street, saying, 'there's two guys in there with a gun,' " Hernandez said.

Hernandez said there was no information suggesting there were any hostages, but a line of people could be seen leaving the Sheridan Center with their hands on top of their heads. Other workers were told to stay in their offices.

The Sheridan Center is across the street from the bank.

Police said they are in contact with one of the suspects, but they are not sure where the suspect is.

Employees who were evacuated from the Sheridan Center were taken to a church in the 300 block of 40th Street. They are being debriefed and then are being released, police said.

Areas of Miami Beach are shut down including 41st Street from Prarie Avenue to Pinetree Drive. Police are advising people to stay away from the area.