UPDATE: The 4-year-old was found in Chicago and taken to Swedish Hospital for an evaluation, police said at approximately 10 p.m.
At around 9:30 p.m., Officers responding to a suspicious vehicle blocking a fire hydrant in the 4000 block of West Belle Plaine discovered the car in question was the subject of the Amber Alert, Chicago police said.
Authorities said the child was found inside the vehicle seemingly unharmed and was taken to Swedish Covenant Hospital for observation.
The offender has not been located, according to Chicago police.
EARLIER: An Amber Alert was issued Monday evening after a minivan with a 4-year-old boy inside was stolen from outside a gas station in south suburban Bridgeview, police said.
At approximately 5:37 p.m., Liam J. Barbarasa was inside a 2001 Oldsmobile Silhouette van outside the 7-Eleven gas station when someone stole the vehicle.
Liam weighs 45 pounds and is four feet tall. He has blond hair and blue eyes and was wearing a black jacket, gray pants with a yellow stripe, white socks and no shoes, police said.
The boy's father told police he went into the 7-Eleven to purchase food, and when he came out, he discovered the vehicle had been stolen.
The minivan was later spotted at 26th and California on the Southwest Side of Chicago, but police weren't able to determine if the boy was inside at the time.
At a news conference in the hours following his abduction, police as well as the young boy's family pleaded for his safe return.
"If anybody knows anything, please," said the boy's aunt. "It's a 4-year-old boy who's innocent. We just want him home safely."
Liam's mother, Maria Barbarasa, said she has no ill feelings toward whoever took the minivan - all she wants is her son back.
"I know you probably didn’t realize he was in there, and that’s ok," she stated. "Please leave him untouched, and just exit the vehicle."
The vehicle is a blue 2001 Oldsmobile Silhouette van with Illinois license plate L703520 and a United States Marine Corps sticker in the back window, police said.
Anyone with information is asked to call 911 immediately.