Updated: GREENWICH, Conn. -- An incident in Greenwich late Thursday that police had initially described as "very serious criminal matter" ended with no arrests, but it remained under investigation, police said.
At about 9:30 p.m., the Greenwich Police Department said via Twitter that it was responding to a "very serious criminal matter."
According to the police department's Twitter, "Round Hill Road in the 600 block is closed to traffic for an investigation in a nearby home." That is near Edgar Road.
The case may involve "a possible hostage situation or barricaded person," NBC Connecticut reported .
A later Tweet from the Greenwich Police Department said: "The initial call was for what appeared to be very serious criminal matter. Currently there is no immediate threat to the general public."
But by about midnight, the department Tweeted, "Round Hill Road is open. Officers are clearing the scene of the investigation. The case remains open while more facts are gathered. No arrest."
Police have not released any further details. The Daily Voice will update the story when more information is available.