MARAWI CITY • Efforts to rescue up to 2,000 civilians trapped in a southern Philippine city by fighting between government troops and Islamist militants failed yesterday when a proposed truce ended in a hail of gunfire and explosions, said the authorities and witnesses.

The civilians were pinned down nearly two weeks ago in the centre of Marawi on Mindanao island, where gunmen loyal to the Islamic State in Iraq and Syria (ISIS) are holding out against a military assault. The government said 178 people had been killed so far.

The local authorities said government officials, working through intermediaries, had reached an agreement with the militants to observe a four-hour ceasefire yesterday to let the trapped civilians leave.

But the officials failed to secure an agreement from their own military for the truce, provincial crisis management committee spokesman Zia Alonto Adiong told Agence France-Presse (AFP). He said rescuers were allowed to access only areas on the fringes of zones held by militants, and were barred from entering bombed-out city blocks.

As a result, only some 170 trapped residents were led to safety, according to the military. "We felt a bit disappointed and betrayed. We're talking about lives of people, my God!" Mr Adiong said. "There are 2,000 people who need immediate help (after) 13 days without food."

Gunfire and explosions, including from artillery shells, later forced rescuers to retreat, according to AFP journalists. There were contradictory reports on who was firing.

"The military... did not approve entry into high-risk areas to avoid putting our humanitarians in danger and any possibility that may complicate the situation," presidential spokesman Ernesto Abella said in a statement.

Mr Roberto Petronio, the chief delegate of the International Committee of the Red Cross in the southern Philippines, said those rescued were mostly men and seemed in fairly good health. In contrast, he said, 14 of the nearly 200 rescued last Saturday had to be hospitalised. "These were mostly children suffering from diarrhoea and malnutrition."

The military has bombarded Marawi with air strikes and waged fierce street-to-street battles with hundreds of gunmen since they began a rampage through residential areas waving the black flags of ISIS.

In all, 120 gunmen including eight foreign fighters have been killed, as well as 38 soldiers and police and 20 civilians, said officials. The civilian toll was lower than previously given.

Scores of people made a dash for safety last Saturday, including a highly respected Muslim politician who had hidden 71 Christians in his home and led 144 people through corpse-strewn downtown streets.

Yesterday's ceasefire deal was initially reached following a meeting last week between President Rodrigo Duterte and the Moro Islamic Liberation Front (MILF), the nation's largest rebel group, which offered to broker a halt in hostilities using contacts with the fighters in Marawi, Mr Adiong told AFP.

Unarmed MILF rebels were to have escorted civilians to safety in a four-hour period ending at noon.

Major Muslim rebel groups such as MILF have signed accords with the government to forge a final peace, giving up separatist ambitions in return for autonomy. But small hardline groups such as the Maute and Abu Sayyaf, which are involved in the Marawi battle, refuse to negotiate and seek to unite behind ISIS.

Indonesian Defence Minister Ryamizard Ryacudu said yesterday there are about 1,200 ISIS operatives in the Philippines; he was speaking at a security forum in Singapore. Philippine defence undersecretary Ricardo David, speaking at the same event, put the figure at 250 to 400.

AGENCE FRANCE-PRESSE