Maryland Transportation Authority Police continue to investigate a report from late Sunday that an adult threw a child off the Key Bridge (Interstate 695) into the Patapsco River.

Yesterday, officers from several police and federal agencies searched the river but found no evidence that the report is true, though police are treating it seriously, said Cpl. Jonathan Green, a spokesman for the authority police.

The scaled-back search was to continue today.

"We have not located anybody or anything at this point," Green said yesterday. "That's one of the issues here, we don't have any witnesses," he said, adding that "everything is leading to something that did happen." He did not elaborate.

Green said the call came in to a 911 dispatch center shortly before 11 p.m. Sunday. Green said investigators are questioning a "person of interest," but he would not say whether that is the same person who called 911. He said the call could have been relayed from any of several receiving stations in the Baltimore area.

"Obviously, this is a very serious situation, and we need to determine what happened and who is responsible," he said. "Unfortunately, we hear about things from time to time that appear to be one thing but are in fact another. We want to get to the bottom of this and determine what happened."

Green said the search has included Transportation Authority police, state police, city police, Baltimore County and Anne Arundel County police, the Coast Guard, a canine unit and at least three police helicopters.