Story highlights Philippines troops clash with militants in southern city

President Rodrigo Duterte cuts short Russia visit to address the crisis

(CNN) Philippines President Rodrigo Duterte has cut short an official visit to Moscow after deadly clashes erupted between Filipino government troops and Islamist militants Tuesday in the southern city of Marawi.

ISIS' media wing, Amaq Agency, put out a statement announcing that "fighters of the Islamic State launch a wide-scale offensive on positions of Philippine troops in the city of Marawi."

Speaking from Moscow, Philippines Foreign Secretary Alan Peter Cayetano said that the violence in Mindanao, one of the Philippines' southernmost islands, was Duterte's priority, despite the high-profile visit to Moscow and St. Petersburg.

"(The Russians) understand that the security of the Filipino people, especially in Marawi and in Mindanao, is a priority," Cayetano said.

"They understand that the presence of the president, President Duterte, is essential in the Philippines. But I will be staying behind. The agreements will be signed."

Philippines President Duterte meets his Russian counterpart in Moscow, May 23.

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