A man distraught about his son's medical condition was in a standoff with police at a hospital in Tomball, Texas, this evening, police said.
The Harris County Sheriff's Office said it had deployed its High Risk Operation Unit, but it was not known whether the man at the Tomball Regional Medical Center was armed.
The sheriff's office first described the incident as a hostage situation, but later said that was not the case.
A supervisor at the county's emergency dispatch center told The Associated Press the situation was in the critical care unit and began around 7 p.m.
Tomball police told ABC station KTRK-TV in Houston that the floor at the hospital where it was happening has been evacuated, but the hospital has not been shut down or put on lockdown.
The man has not made any demands, and negotiations with the suspect were under way, police told the station.
Tomball is about 30 miles northwest of Houston.