MARAWI CITY - The military and police are closely monitoring a town near strife-torn Marawi City after black-clad armed men stormed into the area on Wednesday, officials said.

The town of Bayang, Lanao del Sur, which lies just below Lake Lanao, was gripped with tension Wednesday after unidentified armed men fired at a military detachment in the area.

Col. Romeo Brawner confirmed receiving the report that armed men entered the area and said a very short firefight ensued.

Bayang Mayor Aslanie Balt has since deployed the Barangay Peacekeeping Action Team in different parts of the town.

Both officials suspect that the group's motive was to harass. Brawner also said it was not the same armed group whose identity has been circulating on social media.

Brawner said the military is looking at all angles including the identities of the armed men and the motive behind the attack.

Bayang lies near the town of Butig, birthplace of the Islamic State-linked Maute group, which has been engaged in firefights with state troops in Marawi City for four months now.

The crisis in Marawi City has left more than 800 dead, among them nearly 700 terrorists and over 150 government forces. It has also displaced more than 200,000 Marawi residents and thousands more from nearby towns.

The military earlier said troops are making significant gains, the latest being the recovery of the Masiu or Raya Madaya bridge. With three bridges in the city now regained, the military has full control over all entrance and exit points in the main battle area.

• LOOK: Military reclaims Masiu Bridge in Marawi

During a visit to the conflict zone Thursday, President Rodrigo Duterte said state troops were winding up its offensives. He added that he would lift his martial law declaration over Mindanao as soon as the city has been cleared of hazards, especially of improvised explosive devices.

• READ: Duterte visits Marawi on day of protests