Republican presidential candidate  Ben Carson was in South Carolina campaigning ahead of next month's primary. (Jae C. Hong/AP)

Republican presidential candidate Ben Carson temporarily suspended all campaign appearances Tuesday following news that members of his Iowa staff had been involved in a car accident in the Hawkeye State.

A van carrying three volunteers and a staff member — who was driving — flipped on its side in Iowa and was struck by an oncoming vehicle, according to the campaign.

Carson, during an appearance at the Historic Rotary Club in Charleston, S.C., announced that several of his staffers had been involved in an accident. He described one of those injured as being in "grave condition," according to the Associated Press.

The driver — who is on Carson's paid staff — and two volunteers were transported to the Cass County Memorial Hospital in Atlantic, Iowa. One volunteer was taken to a trauma center in Omaha, according to the campaign.

Carson will travel to Omaha on Tuesday afternoon “to be with the family during this difficult time.”

“Dr. Carson has spoken with the family of the volunteer being transported to Omaha, as well as the attending physician,” the campaign announced in a statement. “Dr. Carson is asking people to join him in prayer for all the individuals and families involved.”

Carson was in South Carolina campaigning in the final stretch before voting begins in the first nominating states.