Smoke wafted from the smoldering carcasses of buildings and houses, with the dome of a mosque blasted out with holes, as Philippine troops battled Thursday to defeat a final stand by the last dozens of pro-Islamic State group militants in a southern city.

The desolate war scene, witnessed by Associated Press journalists on board a navy patrol gunboat in Lake Lanao, could herald what the government hopes will be the end of a nearly five-month siege by the militants in Marawi city.

Filipino troops killed 13 more suspected militants Wednesday night, including one believed to be a top Malaysian terror suspect although his body hasn’t been recovered yet, military officials said.

“Our troops are continuing their assault,” army Col. Romeo Brawner said after his news conference in Marawi was disrupted by loud explosions reverberating from the final area of battle, about 2 kilometers (1.2 miles) away. About 20 to 30 militants continue to fight back, he said.

While troops pressed their assault with artillery and gunfire, officers used loudspeakers to ask the militants, many of them positioned in a bullet-pocked two-story building, to surrender. The building stands on a pier by the lake near a huge gunfire-scarred welcome sign that says “I (love) Marawi.”

Sporadic fighting continued even after President Rodrigo Duterte visited the Islamic city on Tuesday and announced its liberation, sparking hopes that hundreds of thousands of residents could begin returning home. The speed of their return, however, will depend on how quickly the city is declared safe of militants and rebuilt.

Volunteers and displaced residents have begun a government-led cleanup in neighborhoods that were declared safe. Power has been restored in more than half of the lakeside city, along with water supply, officials said.

On Monday, the defense secretary and military chief of staff announced that two of the last leaders of the siege — Isnilon Hapilon, who is one of the FBI’s most-wanted terror suspects, and Omarkhayam Maute — were killed in a gunbattle.

Their deaths were the turning point that partly convinced the president he could declare Marawi liberated from the gunmen, Brawner told the AP.

Military spokesman Maj. Gen. Restituto Padilla said Malaysian Mahmud bin Ahmad was believed among 13 militants killed overnight and another seven in the morning. Six soldiers were slightly wounded in the fighting.