"They gathered all the people who didn't have national identity cards and the people they suspected of being close to the Islamists to execute them," he said, "and put them in two different wells near the bus station."
The soldiers later poured gasoline in the wells and set the bodies ablaze, he said.
The man described seeing at least three people killed in the incident Jan. 10 at the Sevare bus stop, a day before the French launched their military offensive after a surge southward by the Islamists into the town of Konna.
The military blocked journalists Wednesday from reaching the town of Sevare, expanding its security cordon all the way to the town of Djenne. Reporters trying to reach the area, including an Associated Press team, were turned away at checkpoints by soldiers, who cited the national state of emergency and concerns for the journalists' safety.
On Wednesday, the International Federation for Human Rights, or FIDH by its French acronym, called for the creation of an independent commission to look into the crimes and punish those responsible.
FIDH charged that Malian forces were behind about 33 killings - including of ethnic Tuaregs - since new fighting erupted Jan. 10 along the narrow belt between the government-controlled south and the north, which has been under the control of al-Qaeda-linked militants for months.
Malian Army Capt. Modibo Traore said the allegations were "completely false," but declined to comment further.