Parents, teachers and students at a Moorabbin school had a lucky escape today after a massive tree branch crashed to the ground.

The freak accident happened at Southmoor Primary School in Moorabbin at about 9am this morning.

Teachers, students and parents were in the playground waiting for the start of school when the five-metre-long tree branch came crashing down in blustery conditions.

Paramedic Rohan Anstey, who attended the scene, said: "The four women and three children were waiting for the start of school when they heard a cracking sound as the tree branch snapped.

"Thankfully the parents heard the cracking sound and quickly covered the children preventing serious injuries.

"It's fortunate the group was only hit by smaller branches on the limb that fell, and not struck by the full weight of it."

Three children and two women were treated at the scene for minor grazes.

Another woman who suffered cuts and a woman with a knee injury have both been taken to Sandringham Hospital in a stable condition.

School principal Marie Kick told 7News: "We are incredibly lucky...we thank our lucky stars the injuries weren't worse than they are."

WorkSafe and the Department of Education are investigating.

A tree came crashing down at Southmoor Primary School, injuring five people. Photo: 7News.