According to Twitter reports, the explosion came from a trash can in Toontown; an evacuation is underway.

Fire crews are reportedly on the scene:

* * *

Update, 9:10 pm ET:

It’s still early, but at this point we do not see any reports of injuries.

* * *

Update, 9:12 pm ET:

Nothing about the incident on Disneyland’s Twitter feed as yet.

* * *

Update, 9:18 pm ET:

Via L.A. Times reporter Andrew Blankstein, the explosion may have been caused by dry ice in a plastic bottle:

Wikipedia has an entry on a “dry ice bomb” here.

* * *

Update, 10:12 pm ET:

Disney has released an official statement via Twitter confirming that there were no injuries and that the area was evacuated “in an abundance of caution.”

After an investigation by authorities, the park has given the all-clear.