MANILA — The Philippine military said on Sunday that troops had found the bodies of 16 people believed to have been killed by Islamist militants, as fighting continued for a sixth day for control of Marawi City in the southern part of the country.

The discovery of the bodies underlined the civilian toll from the siege, with tens of thousands of residents fleeing the city and the military using aerial bombing and ground troops in an effort to drive the militants from their strongholds.

On Tuesday, President Rodrigo Duterte declared a 60-day period of martial law in the south to expand his authority to fight the militants. Late Friday, he expressed support for the troops by joking that they could each rape three women without suffering any consequences. His comment ignited outrage around the world.

The authorities put the death toll from the six days of fighting at 95, including 61 militants, 19 civilians and 15 soldiers and police officers.