MANILA, July 4 (Xinhua) -- Military authorities planned to impose a "no jacket policy" on people entering Davao City in southern Philippines, to prevent possible suicide bombers from penetrating crowded events or during major festivities.

Colonel Consolito Yecla, Task Force Davao commander, has said the new security measure will be implemented to thwart possible suicide attacks by terrorists off the west coast of Mindanao island in the southern Philippines, mainly in the island provinces of the Sulu Archipelago, namely Basilan and Sulu.

Suicide bombers usually wear jackets or vests to conceal the explosives taped on their bodies.

The additional precautionary measure will be imposed after it is approved by the city government, he added.

"This will only be done when you are approaching the entry points or inspection areas. With this, possible suicide bombers cannot penetrate to the city or to groups of people," Yecla said in a news conference in Davao City on Wednesday.

He added that people can wear their jackets again after the inspection.

The "no jacket policy" is an additional security measure to secure the city. Earlier, the military also imposed a "no backpack policy" in the city.

Yecla urged people in the city to be "the eyes and ears by reporting suspicious persons and unattended baggage."

The new security measure is an outcome of the assessment after the June 28 twin suicide bombing attacks at an army camp in Indanan, a town in Sulu province. The attacks, carried out by two motorcycle riding suicide bombers, left eight killed and 22 wounded, mostly soldiers manning the gate.

Yecla's announcement of the "no jacket policy" came barely three days after Philippine Defense Secretary Delfin Lorenzana voiced concern over the frequency of suicide bomb attacks in the Philippines.

Lorenzana said on Monday the Indanan bombing was the third suicide attack in the Philippines.

The first suicide bomb attack was recorded in July 31, 2018 when a powerful bomb exploded in a van the troops were inspecting at a military checkpoint in Lamitan, a city in the island province of Basilan. A Filipino soldier, five militiamen, four villagers and the driver of the van were killed in that incident.

The second attack took place on Jan. 27 when suspected Indonesian suicide bombers attacked a Roman Catholic cathedral on Jolo, Sulu, killing 23 and wounding more than 100 others.

Lorenzana said the June 28 bombing in Indanan "has raised the level of extremism" in the Philippines.