On Tuesday, New York authorities continued their search for the 14-year-old Queens boy with autism who disappeared Friday after leaving Center Boulevard School in Long Island City, N.Y. Following reports that the boy has habitually taken refuge in train and subway stations in the past, police are now cooperating with transit officials in an effort to move the city-wide search underground.   

Surveillance footage shows autistic Avonte Oquendo running from Center Boulevard School at around 12:45 p.m. Friday. Oquendo, who is also mute, was last seen wearing a gray striped shirt, black sneakers, and black jeans. A statewide missing child alert has been in effect since Monday.

"Anyone out there, any borough, if you see this child please have compassion and please just call the police and say 'I've seen him,'" Oquendo’s mother, Vanessa Fontaine, told NBC New York.

Extensive search and awareness efforts have been conducted in the Queens neighborhood of Rego Park where the boy’s family resides. Over the weekend, police and family members used loudspeakers and posters to alert the public of the increasingly urgent situation.

"We're going on all these leads and nothing has turned up," said Daniel Oquendo, the boy’s father. "It's tough. It's tough because we don't know where he's at or if something is happening to him."

The search intensified on Monday when authorities cut power on the 7 line between Grand Central station and Vernon/Jackson to comb the subway tracks for traces of the boy. After about 30 minutes, power was restored, and the joint search effort continued in the G line tunnels between Bedford/Nostrand and Court Square, NY Daily News reports.

Oquendo is described as being 5-feet-3-inches and weighing 125 lbs. If you have any information about someone matching the description, call the NYPD’s Crime Stoppers Hotline at 800-577-TIPS.