Freezing rain is being blamed for several highway crashes in central and northern Massachusetts that sent dozens of people to the hospital.

Massachusetts State Police say a crash involving 65 cars and three tractor-trailers closed Interstate 290 in Worcester at about 7 a.m. Sunday.

About 35 to 40 people were taken to local hospitals. Two were seriously injured.

A State Police trooper who initially responded to the crash was also rear-ended. Police say she was forced to hurriedly return to her cruiser to avoid cars sliding toward her.

Both directions of the highway were reopened by 11:45 a.m., authorities said.

The National Weather Service issued a freezing rain advisory through 11 a.m. Sunday for much of western and central Massachusetts, northeast Connecticut and northwest Rhode Island.