Lt. Gov. Peter Kinder, a Republican, said the governor, a Democrat, owes an explanation for an "inexplicable" decision to hold back on Guard help.
He said Knowles called him after being unable to reach Nixon. "How does the governor of Missouri not answer the calls, the pleas, of the mayor on the ground?" Kinder asked.
Earlier today, Ferguson Police Chief Tom Jackson raised the question of whether the Guard plan was changed to add to outside political pressure for him to resign.