Thomas Maresca

Special for USA TODAY

MARAWI, Philippines — At a crowded center for refugees fleeing the fighting that has ravaged this city, Merlinda Obedencio never lets her most valuable possession out of sight: a blue cellphone.

It is the only link she has to her husband and three of their six children being held by Islamic State-linked extremists.

Obedencio’s husband, Raul, and their children were captured by the local Maute extremist group during a siege that started May 23 and has left almost 600 dead.

Almost 400,000 people have been displaced by the fighting in Marawi, a city on the southern island of Mindanao, according to the Philippine military. And like Obedencio, most face an uncertain future in a region turned upside down by extremist violence.

The Islamic State, also known as ISIS, views the drawn-out battle as a major win at a time when it is being driven out of its base in Iraq and Syria, bringing greater attention to the Philippines and Southeast Asia as a new beachhead for extremists.

“This is what I consider the first significant example of how foreign fighters from the Syria/Iraq battle space can be brought to bear in another part of the world,” said Thomas Sanderson, director of the Transnational Threats Project at the Center for Strategic and International Studies in Washington, D.C.

After weeks of not knowing whether her family was alive, Obedencio got a call from her husband, who got access to a hidden cellphone. He said he is forced to cook for his captors. He said their 20-year-old son is being used as a human shield on the front lines, while their daughter, 17, was “married” to one of the fighters.

Her husband has since been able to call or text a handful of times, and this contact helps Obedencioda, a devout Christian, keep going.

“For almost two months, I can’t sleep well,” she said. “I’m always thinking of them — are they in good hands? Sometimes when they call I thank God that my family is still alive. I don’t know what we will do after this. All I can do is pray.”

Farhan Macapandia, 23, an English teacher, spent 13 days trapped at home with 11 family members and neighbors after the fighting broke out. The last four days were spent without food, having only rainwater they could collect.

The group finally made a break to safety, carrying only a few essentials. They’re now staying at an evacuation center in the military-controlled compound near the heart of the fighting, where daily airstrikes rattle the buildings and stray bullets are a routine danger.

“We don't have any idea right now if our house is still there,” said Macapandia. ”We don't have money. Our access to work, lost. Our house, lost. Everything, lost. It seems that we need to have a new life, a new beginning.”

While residents blame the extremists for the violence and chaos, many are also growing impatient with the military and its heavy airstrikes, which are leveling buildings throughout the city.

“We are angry at the two sides — ISIS and the military,” said Macapandia’s mother, Nabiliah. “We are trapped here in a war zone.”

The fighting has been contained to a small area of the city, with 60 to 70 militants holding about 100 hostages, said Lt. Col. Jo-Ar Herrera, spokesman for the military’s Task Force Marawi.

The fighting, which initially was expected to end in a matter of days, has killed 427 militants, 99 soldiers and 45 civilians, according to the military.

The Philippine congress voted Saturday to extend martial law on Mindanao until the end of the year. President Rodrigo Duterte had declared martial law for 60 days when the fighting began.

Herrera admitted the battle has “exposed the gaps and weaknesses” in the military’s ability to conduct urban warfare. “We should see the city or urban area as the battleground of the future, and we need to upgrade our capabilities,” he said.

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Among the fighters who were killed are militants from Chechnya, India, Indonesia, Malaysia, Saudi Arabia and Yemen, while fighters from Pakistan and Morocco are still active in the city, the Philippine military said. A greater future danger may be fighters from Southeast Asia returning from Iraq and Syria, said analyst Sanderson.

“Without a doubt, Southeast Asians returning is perhaps the most lethal element of the discussion, because they are coming with the same high-level combat skills that the other combatants have, but these are guys who know the local territory and language,” Sanderson said.

As ISIS loses ground in the Middle East, militants from around this region are moving their operations to Southeast Asia — primarily the Philippines, said Sidney Jones, director of Jakarta-based Institute for Policy Analysis of Conflict,

“The idea that the Philippines is now the destination of choice rather than Syria has sunk in,” she said. “That's definite now.”

Jones warned that the Philippine military is treading a thin line by using excessive force, because of its long history of taking a harsh stance against extremist groups in Mindanao.

“One theme that was used to bring people on board to the ISIS message is the brutality of the security services," she said. “This was before even the airstrikes. So I think there's got to be a serious re-think of how the Duterte administration responds to extremism. Because if they're not careful, they're going to be building a new generation of extremists, not eradicating the generation that's there now.”

Many in Marawi agree that the aftermath of the fight may be the biggest challenge.

“There will be social disorder, political instability, health issues,” said Norodin Alonto Lucman, a well-known former politician and Muslim chieftain.

Lucman, who harbored in his home 74 civilians — including 31 Christians — for 12 days during the conflict before escaping, said many conditions that caused extremism in the first place will be exacerbated by the fighting here.

“We believe that this rebellion in Mindanao is caused by poverty,” he said. “With the Marawi crisis, you reduce thousands more people into poverty — but now they have guns.”

In the meantime, Obedencio waits with her blue phone for news about her trapped family.

"It’s so hard to be a mother trying to look forward to their release," she said. "I pray all the time. It's just a great nightmare.”