MANILA: Rehabilitation of Marawi City which had been ravaged by Daesh-linked terror groups could not go full blast mainly because of the presence of unexploded bombs especially in the main battle area, according to a senior military officer.

Colonel Romeo Brawner, the deputy chief of Task Force Ranao, disclosed that at least 35 per cent of the city has been cleared but soldiers continued to find unexploded bombs, most of which were left behind by the terrorists to stop the advance of government forces.

The other explosive materials consisted of bombs dropped by Air Force planes as well as artillery shells that failed to explode, Brawner added.

In particular, he admitted that the improvised bombs left behind by the Maute Group and the Abu Sayyaf were buried deep in the ground and thus, difficult to excavate.

But despite the problems posed, the military already succeeded in recovering and disposing of a total of 560 unexploded mostly improvised bombs, Brawner said.

To hasten clearing operations with April this year as the target date, Brawner said they have divided Marawi into nine zones, three of which have already been cleared.

The Maute Group and the Abu Sayyaf which have pledged allegiance to the Daesh extremists in the Middle East, laid siege on May 23 on Marawi, the capital city of Lanao del Sur, a component province of the Autonomous Region in Muslim Mindanao (ARRM) along with Maguindanao, Sulu, Basilan and Tawi-Tawi.

The siege prompted President Rodrigo “Rody” Duterte to cut short his state visit to Russia and impose martial law over the whole of Mindanao.

In a joint session of the House of Representatives and the Senate, dominated by Duterte supporters, overwhelmingly voted in late 2017 to extend martial law in Mindanao for another year, with effect from Jan.1 to Dec.31, 2018.

Government forces liberated Marawi in October last year, or five months after the siege that was highlighted by the killing of Daesh-linked leaders Omar Maute and Isnilon Hapilon of the Abu Sayyaf.

Maute founded the group named after him following his return to the Philippines after his studies in Egypt where he imbibed the Daesh teachings, according to the military.