A resident checks the damage on her house as seen through a spyhole in Marawi City on Thursday, April 5, 2018. Froilan Gallardo, ABS-CBN News

MANILA - Rehabilitating all portions of Marawi City affected by the five-month long siege laid by Islamic State-inspired terrorists last year will cost at least P72 billion, officials involved in the rehabilitation of the predominantly Islamic city said Friday.

Bangon Marawi Task Force chair Eduardo Del Rosario said at least P17 billion may be needed for the rehabilitation of Marawi’s “most affected area,” composed of 24 of Marawi’s 96 barangays.

This amount could go up to P20 billion, depending on negotiations between the government and the Bangon Marawi Consortium, a group of Chinese and Filipino firms chosen to build crucial infrastructure and cultural, commercial, and recreational centers in the heavily devastated city.

“We are now undergoing negotiation. And if we will have a successful negotiation, that’s the time that we are going to give that developer what we call original proponent status. And once it is given to him the following day, this will be published in the national dailies so that the Swiss challenge will start,” Del Rosario said in a Palace press briefing.

“It will increase if there are some facilities that the local stakeholders would like to have and if we feel that it is really needed then we will incorporate.”

Del Rosario said the consortium's final proposal will be opened for Swiss challenge from May 4 to 25. The awarding of the contract for the rehabilitation of the most affected area and the groundbreaking will be on May 31 and June 7 this year, respectively, he added.

He explained that the firms which expressed interest in the project were mostly Chinese as these are the ones who have ample capital.

“For them this is very small, but for Filipino companies, that’s massive already,” he said.

Del Rosario said P55 billion of the estimated P72 billion, meanwhile, will be used for the rehabilitation of villages outside the most affected area. This is an upgrade from the P51.6 billion earlier proposed under the comprehensive rehabilitation and recovery program.

Del Rosario also assured Marawi locals that their voice will be heard as the government moves to rehabilitate the city.

“We will [have a] dialogue with stakeholders to discuss and seek feedback for the proposed development of the most affected areas,” he said.