Gun shots and explosions rang out from an entertainment resort in the Philippine capital Manila early on Friday and local media reported armed men were inside the complex.
Resorts World Manila said on social media it was in lockdown and the local fire department said a blaze was burning on the second floor of the building.
“We ask for your prayers during these difficult times,” Resorts World said on Twitter.
Military spokesman Restituto Padilla said the police were in control of the situation and the army was monitoring closely.
Witnesses who spoke to radio stations said several gunmen were seen in the complex. News channel ANC said there were two gunmen, wearing masks and black clothes.
The information could not be immediately verified.
Pictures circulated on social media of the resort, close to the city’s airport, showing plumes of smoke pouring from a building.
A source at one of the resorts told Reuters that employees were being evacuated and declined to give more details.
No group has claimed responsibility.
The Philippines is facing a crisis in the south of the country, where troops have been battling Islamist rebels since May 23. President Rodrigo Duterte declared martial law on the southern island of Mindanao last week.
Duterte has said he fears militant group Islamic State’s “terrible ideology” will spread on Mindanao, an island of 22 million people, and has warned it could become a haven for supporters fleeing Iraq and Syria.