The RCMP says one person is in custody after a report of shots fired that resulted in part of the town being told to stay indoors.
There's no word on charges, however, or the identity of the person in custody and whether shots were indeed fired.
Police were telling some Deer Lake residents to stay inside their homes Thursday around noon, and three schools went into secure school mode.
In a tweet, the Deer Lake RCMP said officers were responding to what the force called "an active incident," and were asking residents of Juniper Street, Maple Street, Willow Place and Tulks Lane to stay inside, as there may be a "public safety threat" in the area. Officers had blocked off entrances to those streets for most of Thursday afternoon.
Police sent an update shortly after 5 p.m. saying the situation was resolved.
Members of Deer Lake's fire department also assisted in controlling traffic.
The secure school protocols were enacted, on advice from the RCMP, a spokesperson for the Newfoundland and Labrador English School District confirmed.
That means the school doors are locked on the outside, but students and staff can still move around inside.
By 3 p.m. NT, buses were arriving to pick up students. Other students were seen walking home.