Philippine President Rodrigo Duterte declared martial law Tuesday in the southern region of Mindanao, after deadly clashes between security forces and Islamic State group-linked militants in a major city there.
The announcement, made by his spokesman at a press conference in Moscow where Duterte was on an official visit, fulfills an often-repeated warning by the president that he would enforce military rule to quell security threats.
"As of 10:00pm Manila time (1400 GMT) Duterte has declared martial law for the entire island of Mindanao," spokesman Ernesto Abella said in the nationally televised briefing.
Abella said martial law would be in place for 60 days, in line with constitutional limits on the use of military rule.
Martial law is particularly sensitive in the Philippines because it was used by dictator Ferdinand Marcos to remain in power during his two-decade reign, which ended in 1986 with a "People Power" revolution.
Mindanao is made up of a large island of the same name, plus smaller islands, and the region of about 20 million people makes up roughly one third of the mainly Catholic country.
Abella and Defence Secretary Delfin Lorenzana later clarified martial law applied to all of Mindanao.
Abella said Duterte would cut short his trip to Moscow and return to the Philippines.
The announcement came after security forces battled dozens of IS-linked gunmen in a built-up area of Marawi, a city of about 200,000 people in Mindanao, on Tuesday.
Marawi is about 800 kilometres (500 miles) south of Manila, the nation's capital.
One policeman and two soldiers were killed in the clashes, which began when police and soldiers raided a house where they believed Isnilon Hapilon, a leader of the infamous Abu Sayyaf kidnap gang and Philippine head of IS, was hiding.
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.
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.
The militants beheaded an elderly German early this year and two Canadians last year after ransom demands for many millions of dollars were not met.
It has also been blamed for the country's worst terrorist attacks, including the 2004 bombing of a ferry in Manila Bay that claimed more than 100 lives.
- IS threat -
The US State Department offers a $5-million bounty for Hapilon because of his alleged terrorist acts against US citizens, including the 2001 kidnapping of three Americans in the western Philippines -- two of whom were killed.
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.
The Maute group has engaged in repeated deadly battles with the military over the past year in rural areas around 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 130,000 lives.
The main Muslim rebel groups are involved in peace talks with the government.
But the Abu Sayyaf, Maute and other hardline groups are claiming they want to set up an Islamic caliphate in the south for IS, according to security analysts.
The fighting on Tuesday came six weeks after the military foiled a mass kidnapping attempt by the Abu Sayyaf on the central resort island of Bohol.
The US and other Western governments also 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.
Duterte, 72, known internationally for waging a war on drugs that has claimed thousands of lives, had said on many occasions since becoming president last year that he was prepared to declare martial law nationally as well as in Mindanao.
"If I declare martial law, I will finish all the problems, not just drugs," Duterte said in March.
However Abella and Lorenzana emphasised on Tuesday that martial law on this occasion remained restricted to Mindanao.