Parents have been streaming in to take their kids home from Benjamin Tasker Middle School in Bowie after a boy was shot and critically wounded outside the school.
The boy's aunt, who had driven him to school, took him to a hospital after he was shot.
Officials said he's in critical condition after losing a lot of blood.
Police are looking into whether the shooting is linked to a string of sniper-style shootings in the region last week that claimed six lives.
Investigators from nearby Montgomery County, the scene of most of last week's killings, are on the scene of the latest shooting.
A police spokeswoman said there's no information yet to link the shooting to the others.
Prince George's county schools are in a lockdown mode.
In Montgomery County, afternoon kindergarten has been canceled and outdoor school activities suspended.