A woman accused of driving a minivan into the Atlantic Ocean with her three children in Florida was arrested Friday on three counts of attempted first-degree murder, Volusia County Sheriff Ben Johnson said Friday afternoon.

Investigators say they think Ebony Wilkerson was trying to kill her children -- ages 3, 9 and 10 -- when she drove into the surf in Daytona Beach on Tuesday, Johnson said.

"She actually told them to close their eyes and go to sleep, she was taking them to a better place," he said.

Bystanders and beach rangers went into the water and rescued the children, witnesses and police said. Wilkerson tried to keep rescuers from pulling her children from the minivan and at one point was fighting her son for control of the steering wheel, Johnson said.

Johnson said Wilkerson told investigators she was trying to drive out of the surf, not into it, and has denied trying to harm her children.

While there is no evidence that drugs or alcohol was involved, Johnson said one goal of charging her was to make sure she gets help for any possible mental issues.

"This is a tragic event. And our goal is to get her into the system so that we can protect the children and take whatever action we need to help her, too," he said.

Wilkerson also is being held on three counts of aggravated child abuse, Johnson said. She has not yet requested an attorney, he said.