There was a short lockdown at Oliver Elementary School Monday after a young girl was sexually assaulted by a man hiding in a stall in the girls' washroom.

The Grade 2 student was grabbed by the man when she went to the washroom on her way out for recess, police say.

"She entered the bathroom, and quickly realized she was not alone," says Jeff Wuite, spokesperson for the Edmonton Police Service.

"There was a strange male in one of the stalls in the girls' bathroom. He grabbed her, sexually assaulted her, then left the bathroom – at which point she quickly contacted a teacher who contacted police."

Wuite says the girl is being treated in hospital. He says she suffered a bump on the head, but there was "no indication of any violent injuries."

The man fled, and police are still searching for him.

The suspect is described as a black man, about 30 years old, with puffy hair with orange streaks in it. He was wearing a red shirt and baggy dark pants.

Anyone who sees this man is asked to call police.

A spokesperson for the Edmonton District School Board, Jane Farrell, says the school held an assembly with students early Monday afternoon to tell them what happened.

She says counsellors are available for any students who may need them.

She also says the board will review security procedures in light of the incident.