LITTLE ROCK, Ark. — Prosecutors are considering filing charges against a 21-year-old driver who struck and injured a group of bicyclists traveling through Arkansas on a cross-country trip, a prosecutor said Wednesday.

Authorities are investigating why the driver crashed into a group of 13 cyclists on Tuesday afternoon near McCrory, about 90 miles northeast of Little Rock.

Prosecutor John Bell said Wednesday there wasn't any evidence of alcohol in the driver's bloodstream, but he said authorities were looking into whether anything else, such as a cellphone, was involved in the crash.

"There are some charges that could be filed just off the immediate evidence ... based upon just the fact that the driver was traveling on a relatively flat stretch of road in broad daylight and the bicyclists were on the highway in plain view," Bell said.

Seven of the 13 cyclists were sent to area hospitals, according to Overland, a Williamstown, Mass.-based company that organized the group's six-week trip from Charleston, S.C., to Santa Monica, Calif.

"A vehicle struck the leader at the back of the group and then struck the next six bikers in the line," Overland director Jonathan Igoe said. "Those were the seven bikers whose injuries required immediate medical attention."

Five of the seven injured cyclists remained hospitalized Wednesday, including one person in critical condition, the company said.

The cycling group, which is made up of 11 high school students from across the country and two adult guides, was two weeks into its trip when the car ran into some of the bikers on Arkansas State Highway 17, Igoe said.

Six students and one guide were initially hospitalized, Igoe said. He wouldn't say whether the guide or one of the students remained in critical condition Wednesday.

The group was headed to nearby Newport to spend the night on Tuesday, Igoe said. But after the crash, a community member in Arkansas opened up her home to the cyclists, Igoe said.

As for what happens to the rest of the planned trip, Igoe said it's too early to tell.

"That's a question that we're going to be trying to answer over the next couple of days," he said.