7:18 AM PT -- THE DOG IS SAFE!!!!! Law enforcement officials tell TMZ ... Amanda's dog was claimed by her parents after she was placed on a 5150 hold.
Amanda Bynes accidentally drenched her pet Pomeranian with gasoline while building a fire in a residential neighborhood ... then raced to a nearby liquor store to clean the pooch ... and TMZ has the bizarre footage.
The surveillance video -- taken inside the liquor store -- begins minutes after Bynes allegedly used a canister of gasoline to fuel a fire outside a random elderly woman's home in Thousand Oaks, CA around 8:38 PM on Monday night.
At 8:39 PM ... Bynes can be seen bursting into the liquor store and darting straight for a restricted "employees only" area -- while holding the dog in her outstretched arms.
The cashier -- sensing something was wrong -- rushed out from behind the register and chased after Bynes to see what she was doing.
TMZ spoke to the owner of the store who tells us ... the cashier detected a strong odor of gasoline and observed Bynes attempting to rinse off the dog in a sink in the back area.
We're told ... as soon as the cashier confronted Bynes, she "freaked out" and left the store without further incident.
Moments later, cops located Amanda and placed her on a 5150 psychiatric hold believing she could pose a danger to herself and/or others.
As for the dog, it's current whereabouts are unknown ... but we're trying to track it down.