Four people were missing and eight injured Saturday after an early morning collision between two flat-bottom boats on the Mississippi River in Iowa.

The crash occurred in the O'Connell Slough area off Burlington, Iowa, shortly before 2 a.m., The (Burlington) Hawk Eye reported. Kevin Baskins, a spokesman for the Iowa Department of Natural Resources, said the darkness made locating everyone involved difficult.

By Saturday afternoon, Baskins added, the search was "leaning more toward recovery." Relatives and volunteers continued a land and river search.

One of the boats was carrying a single person and the other 11, investigators said. Both were jon boats, flat-bottomed aluminum boats used by hunters and fishing parties.

Three of the missing are men and one a woman, all believed to be in their 20s, officials said.

One of the injured was airlifted to a hospital in Iowa City while the others were treated locally.

Baskins said the investigation into the cause of the collision is likely to take weeks, and the survivors have been conflicting stories of what happened.

"You don't have skid marks and stuff in boating accidents," he said.

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