CONCORD, N.H. (AP) — Snow-covered roads led to many accidents in parts of New Hampshire on Thursday, as a number of school districts are staying closed for another vacation day and some flights are being delayed at canceled at Manchester-Boston Regional Airport.

State police temporarily closed a busy section of Interstate 93 northbound just south of the Interstate 89 junction in Bow because of accidents involving at least nine vehicles Thursday morning, including two tractor trailers. Three people were taken to hospitals with injuries; their conditions weren't immediately known. The road was reopened by noon.

Some schools said they'd close Friday, too.

Snow fell across much of the state and the Department of Transportation lowered speeds to 45 mph on sections of I-93 and 89. The snow was expected to pick up Thursday night.

Gov. Maggie Hassan encouraged residents to exercise common sense in following all traffic and safety alerts during the long-duration storm, which was accompanied by falling temperatures.

"This is a cold storm and black pavement can be deceiving when anti-icing chemicals have limited effectiveness," said Bill Janelle, director of operations for the Transportation Department. "Conditions in many locations may be worse than they appear. Right now the message is slow down! No motorist should be currently going more than 45 MPH on any New Hampshire road."

About 6 to 10 inches of snow is expected in the southern half of New Hampshire, and up to a foot in the Seacoast area. Lesser amounts are expected farther north. Biting cold and gusty winds are expected to make matters worse.

The storm is expected to last into Friday morning.

Join our Newsletter for the latest news right to your inbox