With scorn for Mr. Diarra, the coup leader, Capt. Amadou Sanogo, said in an interview on state television Tuesday night, “Cheick Modibo Diarra has not given a thing, one single piece of equipment, to the Malian Army.”

Several soldiers and police officers guarded Mr. Diarra’s expansive villa at the edge of town here Tuesday. A request to see Mr. Diarra was turned down by soldiers, who said he was inside “resting.”

The prime minister’s fall from grace, via a military that had helped install him nine months ago, was as sudden as it was steep. He was appointed last spring as a caretaker prime minister until new elections, halted by the coup, could be organized.

Early Tuesday, after Mr. Diarra was hauled to the camp at Kati, outside the capital, Captain Sanogo, who led the coup in March, told him there was proof “against him that he was calling for subversion,” said Mr. Mariko, the military spokesman. “He had recorded cassettes that were going to be broadcast on ORTM,” the state broadcaster, Mr. Mariko said. “These cassettes called on the people of Mali to go into the street to oppose the army.”

But a more likely explanation was a growing and public clash about the best way of chasing the Islamists from the north.

Mr. Diarra, derided as an amateur politician by the well-entrenched political class here, has nonetheless been steadily raising his profile at the expense of Captain Sanogo. He has made the rounds of foreign capitals to push his view that reconquering the north required immediate international military assistance. Captain Sanogo has rebuffed suggestions that the Malian Army is incapable of handling the job on its own. Indeed, for weeks, the captain resisted the idea that troops from other African nations should even go near the capital.