A flash flood emergency was declared Tuesday night for the city of Frederick, Md., authorities said, describing the situation as “particularly dangerous.”

The National Weather Service said at 9 p.m. that up to six inches of rain had already fallen in places, with more expected.

The weather service, quoting Frederick emergency management, said widespread flash flooding had already occurred in and near Frederick.

The flash flooding “may continue to worsen,” the weather service said.

“This is a particularly dangerous situation,” the weather service said. It urged poeple to “seek higher ground now.”

Numerous water rescues had been made in and near Frederick, the weather service said, adding that water had been reported inside buildings.

Many roads were flooded, the weather service said.

Storm damage was also reported in northern Virginia, as storms rolled into the area near the Capital Beltway.