MANILA - The Department of Health (DOH) sees a looming humanitarian crisis as thousands continue to stay in evacuation centers due to the ongoing siege in the Islamic city of Marawi.

DOH Usec. Herminigildo Valle on Tuesday said that as the crisis goes on in southern Philippines, more evacuees have gotten ill in evacuation centers.

“As crisis goes on we’ve seen more and more of those evacuees starting to get illnesses and suffering the effects of difficult environments,” he said on ANC’s “Beyond Politics”.

Residents displaced from conflict-torn Marawi have been reporting illnesses, including fever and diarrhea, as they were forced to stay in evacuation centers amid the ongoing government offensive against Maute terrorists in the city.

Most of the displaced have been staying in evacuation centers in Marawi's neighboring Iligan City.

Valle also raised concerns on evacuees staying at home instead of evacuation centers.

“As time goes, the consumption of our emergency relief resources are increased and we need more and more support and additional commodities,” he said.

Valle said he hopes crowded evacuated centers can be decongested in 4 to 12 weeks.

Due to sanitation issues, Valle said health workers noticed 5 most common illnesses seen in evacuees: coughs and colds, watery diarrhea, skin allergies, influenza-like diseases, and hypertension.

The DOH is also working to get in touch with other agencies to help provide more facilities for evacuees. He said the department has also began addressing cleanliness issues to avoid spread of possible diseases.

“We have start cleaning up the waste around the area, the portalets that we have placed there,” he said.

Valle said addressing the health and sanitation concerns of evacuees is a challenge due to security threats brought about by the ongoing clashes.

"We just want to invoke the non-combatant status of civilians, injured, pregnant women, children and health workers as well," he said.

The United Nations Children's Fund (UNICEF) Philippines also raised concerns on sanitation issues in evacuation centers, particularly the safety of drinking water available to evacuees.

Government forces were met with resistance by Abu Sayyaf and Maute extremists in Marawi City on May 23 after soldiers tried to arrest Abu Sayyaf senior leader Isnilon Hapilon. As of Monday, the military said 257 militants, 62 soldiers and 26 civilians had been killed. Hundreds of people are unaccounted for, believed to be hiding in the basements of the city.--with a report from Reuters