From CBS News:
Officials say what appears to be dry ice in a plastic bottle caused a small explosion at Disneyland, bringing evacuations but no reports of injuries.
Anaheim police spokesman Sgt. Bob Dunn says the blast was reported at 5:30 p.m. Tuesday in Disneyland's Toontown area, which was evacuated as a precaution.
Police are investigating and an Orange County sheriff's bomb squad was headed to the scene.