2:03 PM — a Disneyland offical tells TMZ … This afternoon, building materials being used by a contractor produced a reaction backstage at the theme park … and the area was examined by appropriate response teams.

Several cast members were treated on-site by paramedics and released … and we’re told at least five employees experiencing dizziness and shortness of breath were transported to local hospitals.

Out of an abundance of caution, adjacent areas were cleared of guests — and are expected to reopen soon.

Scary situation at Disneyland … multiple people have been hospitalized following a hazardous materials incident.

The Anaheim Fire Department tells TMZ … crews are currently at the famous California theme park for a hazmat situation … and four people have been taken to a local hospital.

All four are Disney employees who began feeling sick due to an unknown odor in the backstage area near the Star Tours attraction.

According to social media posts, Star Traders, the shop connected to the Star Tours attraction, has also been closed, and cast members have reportedly been blocking all entrances.

The employees experienced dizziness and shortness of breath.  The cause of the odor is unknown at this time. There are no concerns with any park guests at this time.

We’re out to Disneyland for more info … so far, no word back.