Times Square Panic After Motorcycle Backfire Causes Multiple Injuries

More than a dozen Times Square tourists are nursing injuries after fears an active shooter was opening fire caused mass chaos -- but it turns out, it was just a bunch of motorcycles backfiring.

The scene around 10 PM Tuesday was insane ... hundreds fleeing in all directions, stampeding over each other as they sought cover. Some ran into packed Broadway theaters which brought productions to a halt.

In the panic, several people suffered broken bones and lacerations -- multiple slammed their heads into signs and other displays as they fled. The scene clearly reflects the nation's uneasiness after last weekend's mass shootings in El Paso and Dayton.

NYPD says what really happened is a group of people on motorcycles rode through the Square with their engines backfiring as they went -- and that sound caused the mass panic.

Cops are now using surveillance cameras to try to identify the motorcyclists ... and we're told they could be charged with reckless endangerment.