WALTHAM (CBS) – A State Trooper is recovering from minor injuries after a driver crashed into his cruiser on Route 128 overnight.

It happened in a work zone on 128 south in Waltham near Route 20 just after 4 a.m.

The car slammed into the back of the cruiser, which had a police dog inside. It was not hurt.

The driver was taken to Newton-Wellesley Hospital for treatment.

There’s no word yet on what caused the crash or if there will be charges.

A trooper was struck on the elbow while making a traffic stop. (CBS)

The area was re-opened to traffic around 6 a.m.

In a second incident Tuesday morning, a State Trooper was taken to the hospital with minor injuries after he was struck in the elbow by a passing car on Route 128 southbound in Lynnfield.

The State Trooper was hit around 9:44 a.m. as he was conducting a traffic stop on the side of the road.

Both incidents remain under investigation.