Officials estimate there are more than one million unlicensed firearms in circulation in the Philippines, with dozens of people killed each election season when politicians seek to eliminate rivals or critics.
Fuelling the violence are the "private armies" controlled by so-called political warlords.
The gun ban is imposed ahead of every Philippine election, but has taken on more significance in recent months following the massacre of 57 people in the southern province of Maguindanao late last year.
Under the terms of the ban, which will last until June 9, civilians with permits to carry guns are also forbidden from taking them out of their homes.
In addition, politicians are not allowed to have armed bodyguards, a common practice normally.