The same penalty applies to those who arrange or formalize unions with minors.
The impoverished Southeast Asian country ranks 12th in the world for child marriages, according to the UK-based group Plan International. Long-standing cultural practices and gender inequality make change difficult.
“The State … sees child marriage as a practice that constitutes child abuse because it corrupts, degrades, and belittles the intrinsic value and dignity of children,” the law states.
According to the government, the law is consistent with international conventions on the rights of women and children.
However, parts of the law were suspended for a year to give a transition period to Muslim and indigenous communities for which the marriage of minors is relatively common.
A UNICEF report last year noted that more than 500,000 girls and women worldwide were married in their childhood, with the highest levels in sub-Saharan Africa and South Asia.
Recent data indicates that the practice is in decline around the world.