Shin Bet agents have joined Israel Police in the search for four-year-old Yuval Kogan, who disappeared after being seen at Hofit Beach in Ashkelon on Thursday morning.

The boy was last spotted near the shore wearing a green shirt. He is slim with brown hair and had been with his father on a local outing. The pair became separated, and the father alerted police upon noticing the child was missing.

Almost 24 hours after the disappearance, the boy's mother, Dina, told Walla that she is urging all possible helpers and rescuers to join the effort. She expressed deep worry and fear that a kidnapping may have occurred.

President Isaac Herzog contacted Dina Kogan by phone to convey concern, offer family support and confirm ongoing coordination with Police Commissioner Daniel Levy and Shin Bet Director David Zini.

Hundreds of officers and volunteers continue the search into the night using air, sea and land assets along with advanced technology and rescue units.

Following the initial report, police sent helicopters, marine units, divers, municipal rescue teams and other responders. Focus remains on the shoreline and nearby zones.

Teams are covering the northern coast of Ashkelon up to Nitzanim. The sandy dunes offer many high and low spots plus hiding places, and concern for the child rises with each passing hour.

United Hatzalah deployed its Drone Unit with a command center and multiple drones, while volunteers searched on foot.

Southern District Police head Assistant-Chief Chaim Bublil led an on-site assessment with senior officers and rescue leaders, then ordered expanded nighttime operations using all available police resources.

Ashkelon Mayor Tomer Galam visited the scene and noted that municipal inspection and policing teams are assisting Israel Police.

Police urge the public to stay alert and to call the emergency hotline at 100 or the Ashkelon station with any helpful information.

Officials repeated the request, directing anyone with details on the child's location to contact 100 or the Ashkelon station at 08-6771440.

Israel Police routinely mount large multi-agency searches for missing children, combining units, aerial support, marine teams, rescue groups and local authorities to locate individuals quickly.