CEDAR LAKE, Ind. (CBS) -- Two off-road vehicles broke through the ice in Cedar Lake, Indiana and sank Sunday.

Cedar Lake police were called Sunday for a utility-task vehicle that had broken through the ice on the north end of the body of water Cedar Lake near Potawatomi Park and Meyer Manor.

The operator of the utility-task vehicle and his son were safe on the shore when police got to the scene, but they had earlier found themselves in deep water — and their Polaris UTV was sunken all the way down to the roof.

Other off-road vehicles rushed to the scene, and before police could get them away, a two-wheel off-road vehicle also broke through the ice and sank, police said. The operator of that vehicle got onto another UTV and fled, police said.

Anyone with information on the operator of the white two-wheel off-road vehicles was asked to contact police.

Both off-road vehicles remained submerged in Cedar Lake Sunday night, with recovery planned for Monday, police said.

Police emphasized that the area of the lake where this happened is not frozen or safe to drive an off-road vehicle over. Water runs under the ice from inlet to inlet, causing shelf ice and open water, police said.

Ice races held Sunday brought several off-road vehicles to the area, and the designated area for the ice races is safe and regulated. But those in charge of the ice races  have no control of what others do outside of the event, police said.

Cedar Lake police also emphasized that those who brought off-road vehicles for the ice race had to have them registered to be on a property other than their own — and that off-road vehicles are not street legal on any roadway.

The Indiana Department of Natural Resources is investigating.