A 6-year-old boy was presumed drowned Saturday evening after disappearing while wading in the Mississippi River off Boom Island near downtown Minneapolis.

The child was among five young friends with two adults on a bike ride when some of the children decided to step into the river, according to a news release from the Hennepin County Sheriff's Office.

Three of the children went too far into the water and began to struggle. One adult was able to rescue two of the children, but the 6-year-old slipped away, the sheriff's news release said.

Andy Skoogman, a spokesman for the Sheriff's Office, said the river depth drops substantially close to the shoreline and the current runs hard so the children didn't go far before they ran into trouble.

Assistant Minneapolis Fire Chief Bryan Tyner said the 911 call came about 6:20 p.m. The department searched by boat, helicopter and sonar but was unable to locate the boy. About two hours later, Tyner said Hennepin County Sheriff's divers began searching underwater for a body.

No additional information was available late Saturday.

Rochelle Olson • 612-673-1747

Twitter: @rochelleolson