A Philippines military commander says ongoing delays in rebuilding the city of Marawi, which was destroyed during five months of combat against Islamic State-inspired militants, could see the recruitment of more "enemies of the state".

Key points: Marawi has been under martial law for more than a year since it was liberated

Marawi has been under martial law for more than a year since it was liberated Unexploded bombs dropped during air strikes a danger for demolition teams

Unexploded bombs dropped during air strikes a danger for demolition teams 62,000 people people are still displaced, with many living in tents

It is almost a year since the relatively small band of combatants was forced to retreat, after a fierce campaign of air strikes, artillery shelling and house-to-house combat.

Since then, the city centre, known locally as "ground zero", has remained off limits to its former residents, and the huge task of clearing the shattered neighbourhoods has not even started.

With 62,000 people displaced, many of them still living in tents, frustration at the lack of action is starting to fester.

"When it comes to bombing our houses and our communities the Government is very quick," Drieza Lininding, chair of the Moro Consensus Group, said.

"But when it comes to rehabilitation, they cannot even afford to allocate the money for us."

That growing frustration, along with ongoing poverty and minimal education, is a dangerous combination in a region where Islamic State recruiters are still known to be operating.

"Of course there's that danger, that if we delay the development of this area we create more enemies of the state," Colonel Romeo Brawner, spokesperson for Joint Task Force Ranao, said.

"But we are continuously in dialogue … Really there is progress that is happening."

Since June 2017, Australia has committed $24 million in aid for displaced residents and peacebuilding efforts, including $3 million for school meals through the World Food Program.

Marawi city centre lies in ruins

Government troops battled IS-linked militants in Marawi city for five months under martial law. ( Reuters: Romeo Ranoco )

Walking through "ground zero", where IS declared a caliphate in South-East Asia last year, it is easy to think the city has been forgotten.

The once-thriving, historic city centre lies in ruins, with huge holes blasted out of concrete walls and every surface riddled with bullets holes.

Every now and then the word "ISIS" is spray-painted on walls, though there is some suggestion many of the "signatures" were actually written by the military.

An eerie silence still hangs over the city, and there is only the sound of birds, crickets and the occasional creak of metal.

Now nature has started to reclaim the city. Thick weeds are growing over the rubble, vines climb up indoor staircases and ferns peep out of bullet holes.

Unexploded bombs pose danger for demolition teams

Colonel Romeo Brawner believes martial law should be extended beyond December 31. ( ABC News: Phil Hemingway )

The Philippines military has recovered 3,000 unexploded bombs since the start of the siege in May 2017.

But Colonel Brawner said there were still many more unaccounted for, including 50 unexploded general purpose bombs, known to have been dropped on the city during air strikes.

He said that presented a serious danger for demolition teams.

"There's that danger that once the heavy equipment comes in they might hit a bomb accidentally," he said.

One attempt to bring in developers to recover the city failed, when the China-Philippines consortium failed to meet financial guarantees and the residents voiced concerns about China's involvement in the project.

The military said recovery teams would "break ground" this month or next, but residents said they had been hearing that each month since May.

First election where 'not a single fatality' was recorded

Marawi was declared liberated from IS-linked fighters on October 17., 2017. ( Reuters: Romeo Ranoco )

There are some positive signs of progress.

The Marawi region has just held relatively peaceful elections for village chieftain, known as Barangay elections, which were delayed for a year due to security concerns.

The ABC was in Marawi during the elections and visited several polling stations, which were all overseen by heavily armed soldiers.

Despite big crowds, and a lot of noise, there was no indication of violence or vote rigging.

A military statement said there had been "heated arguments" and "isolated fist fights" but the statement claimed it was the first election in Marawi where "not a single election-related fatality" was recorded.

Colonel Brawner said the reason for the relative peace was the heavy military presence in the region.

Martial law has been operating here for more than a year, and Colonel Brawner believes it should be extended beyond December 31, when it is scheduled to finish.

"Prior to the siege there was a killing almost every day here in Marawi city," he said.

"We can even consider Marawi city the safest city in the entire country now."