A Catholic bishop and a top-ranking Muslim cleric have condemned the desecration of a cathedral and the destruction of its holy images by an Islamic group in Marawi, the Philippines.

Two weeks ago, a group of Maute gunmen, a radical Islamist terrorist group, laid siege to the city and sparked fear among members of the public.

Members of the Muslim Darul Ifra, the most authoritative religious group in Marawi, branded the act as 'un-islamic' on Wednesday. Regional governor Abu Huraira Udasan also denounced the attack on St Mary's Cathedral and declared it as 'haram' or forbidden. Usasan also urged people not to allow the incident to cause division between Muslims and Christians in the region.

In a public statement, members said the Quran does not order Muslims to desecrate non-Islamic worship sites or to persecute leaders of other regions and so the destruction of statues and other religious symbols was absolutely against its teachings.

Chairman of the regional peace and order council, Mujiv Hataman, also said vandalism of non-Islamic worship sites is a serious offence in Islam.

Speaking to Philstar Global on Wednesday he said: 'The destruction of the church in Marawi City was done by people who are introducing themselves as Muslims but are not adhering to the teachings of Islam.

'They are so reckless in quoting verses in the Quran in perverse manners to suit their perverse interests. They are unworthy of promises of divine graces from Allah.'

Rt Rev Edwin de la Peña, Bishop of Marawi, condemned the desecration of the cathedral, the burning of the cathedral, calling the gunmen's act 'trampling on the Catholic faith'. 

In a report posted on the news website of The Catholic Bishops' Conference of the Philippines (CBCP), he labelled the actions as 'blasphemy' and 'unacceptable'.

'It's obvious that their actions are really out of this world. It's demonic.We are angered by what happened. Our faith has really been trampled on,' De la Peña said.

The parish priest of Marawi City, Fr Teresito Suganob, was snatched by the gunmen who attacked and vandalised St. Mary's Cathedral on May 23.

As well as Suganob, more than 10 others, three of whom were volunteer church workers, were also taken by terrorists as they fled the scene when soldiers arrived to drive them away.

The Islamist militants have been reduced to a 'small resistance' after troops crippled their logistics and some fighters have fled from the battle, military officials said on Thursday.

'In a few more days it could be over'" armed forces Chief of Staff General Eduaro Año told ANC television on the 17th day of a siege by hundreds of militants who have sworn allegiance to the ultra-radical Islamic State group.

A video of the attack on the St Mary's Cathedral can be watched below.