Human Rights Watch (HRW) urged Somalia's parliament Friday to reject a constitutional amendment that aims to lower the age of majority, claiming it would "weaken rights protections for children".

The proposed changes, which will be debated on Saturday, make a distinction between the age of maturity at 15 and the 18-year age of responsibility.

The NGO said in a statement that this suggested that "everyone under 18 would remain protected by juvenile justice standards".

"However, in practice, this new age of majority risks reinforcing existing ambiguities in Somali law around the age of majority that could heighten children's vulnerabilities," HRW said.

It said the proposed change to set the age of maturity at 15 "would place girls in particular at greater risk of child marriage, which affects their health, notably reproductive health, their access to education, and their protection from other forms of abuse," the rights organisation said.

Somalia, located in the Horn of Africa, is one of the least developed countries in the world.

According to the international organisation Girls Not Brides, 26 percent of girls in Somalia are married before the age of 18, and 17 percent before the age of 15.

The adoption of the amendment would also be, according to HRW, "contrary to Somalia's obligations under the United Nations Convention on the Rights of the Child, which defines a child as anyone under 18".

According to the NGO, children have previously been arrested and detained as adults.

For more than 16 years, Al-Shabaab has waged a deadly insurgency against the fragile central government in Mogadishu.

HRW said it found that authorities across Somalia during President Hassan Sheikh Mohamud's first term in office "threatened, beat, and in some cases tortured boys in custody" who they believed to be affiliated with the group.