Iligan: Islamist militants who triggered martial law in the southern Philippines when they rampaged through a city are threatening to kill a priest and other hostages, the Catholic Church said on Wednesday.

President Rodrigo Duterte imposed martial law across the southern region of Mindanao on Tuesday after the militants, who have declared allegiance to the Islamic State group, battled with security forces and burnt buildings.

Duterte warned the martial law would be ‘harsh’ and like a dictatorship in an effort to quell not just the gunmen in Marawi, a mostly Muslim-populated city of 200,000 people, but the rising threat of IS-inspired militancy emanating from Mindanao.

The gunmen raided a church in Marawi and took the local priest, Father Chito Suganob, plus an unspecified number of other people hostage, according to the head of the Catholic Bishops’ Conference of Philippines, Archbishop Socrates Villegas.

‘They have threatened to kill the hostages if the government forces unleashed against them are not recalled,’ Villegas said in a statement.

A regional military spokeswoman said Villegas’s report had yet to be verified.

The fighting erupted on Tuesday after security forces raided a house in Marawi where they believed Isnilon Hapilon, a leader of the infamous Abu Sayyaf kidnap-for-ransom gang and Philippine head of IS, was hiding.

The United States regards Hapilon as one of the world’s most dangerous terrorists, offering a bounty of $5 million for his capture.

More than 100 gunmen responded to the raid by burning buildings and conducting other diversionary tactics, according to Defence Secretary Delfin Lorenzana.

Photos posted on social media by residents showed the gunmen walking through the streets of Marawi and placing black flags that looked similar to those used by IS.

Lorenzana said on Tuesday night that many gunmen were hiding in buildings as snipers, making it difficult for security forces to combat them.

Thousands flee

Thousands of residents fled Marawi, according to an AFP photographer at a military checkpoint near Iligan, the next biggest city about 40 kilometres (25 miles) away.

‘We heard a lot of gunfire and explosions yesterday. We hid inside, we were too frightened to go out,’ Noraisa Duca, a Muslim resident of Marawi, told AFP at the checkpoint.

The gunmen killed one policeman and two soldiers on Tuesday, authorities said.

They reported further skirmishes overnight in Marawi but on Wednesday afternoon it was unclear how many militants were still in the city or if they had escaped into nearby mountains and forests that they have long used as hideouts.

The Abu Sayyaf, based on the most southern islands of Mindanao, has kidnapped hundreds of Filipinos and foreigners since the early 1990s to extract ransoms.

Security analysts say Hapilon has been trying to unite Filipino militant groups that have professed allegiance to IS.

These include the Maute group, which is based near Marawi.

Muslim rebels have been waging a rebellion since the 1970s for an independent or autonomous homeland in Mindanao, with the conflict claiming more than 120,000 lives.

The main Muslim rebel groups are involved in peace talks with the government.

But the Abu Sayyaf, Maute and other hardline groups want to set up an Islamic caliphate in the south for IS, according to security analysts.

The US and other Western governments warned this month that terrorists were planning to kidnap foreigners in tourist hotspots in the western and central Philippines, adding to longstanding advisories of abduction threats in Mindanao.

‘Dont be scared’

‘Our fellow Filipinos, do not be too scared,’ Duterte said early Wednesday from Moscow, where he had just begun an official visit that he abruptly ended to fly home and deal with the crisis.

Duterte vowed to be ruthless in quelling the terrorism threat in Mindanao, drawing parallels with martial law imposed by dictator Ferdinand Marcos during his two-decade rule that ended with a ‘People Power’ revolution in 1986.

Duterte also said that martial law in Mindanao, home to roughly 20 million people, could last up to a year.

Critics of Duterte, who has waged a controversial war on drugs that has claimed thousands of lives, have feared that he may use various security threats as an excuse to impose a form of authoritarian rule.