NASHUA — Weather forecasters and state officials warned of a snowy, slippery commute Friday morning but slick roads led to a spate of crashes even before the heavy snowfall.

Just before 9 p.m. Thursday, Nashua police officials said they received reports of car crashes from the north to the south of the city.

One crash involving multiple vehicles on the F.E. Everett Turnpike near Exit 4 when the road became “a sheet of ice,” police officials reported.

There was a three-car crash at the intersection of Nashua Drive and Canal Street in the city’s downtown just after 9 p.m., officials said.

Another accident took place at 20 Kessler Farm Road, which is the northern part of Nashua off Exit 7W, when a single motorist overturned his car.

He was treated at the scene for an unknown injury, officials said.

Then at 9:30 p.m., Nashua police officials confirmed another accident caused by slippery conditions at 106 Amherst St. near the entrance to Edgewood Cemetery.

Londonderry police officials reported a car crash with injury just before 9:45 p.m. on Stonehenge Road in town at the intersection with Perkins Road.

Meanwhile, Pelham police officials warned the public that their roads had gotten “icy and slippery” even before snow had fallen.

Most school administrators had not made their decisions by late Thursday about whether to cancel or delay school on the next morning.

Some had already put off the Friday start by two hours including schools in Berlin, Newport, Sunapee, Windham, Littleton and Lempster.

In the Great North Woods, school officials by Thursday night had called off school for the entire next day in Errol, Gorham, Milan, Shelburne, Randolph and Dummer.