(CNN) -- Somalia's Al-Shabaab has brushed aside accusations from Human Rights Watch that the Islamist militia recruits child soldiers, saying that Islam considers people to be adults from the age of 15.
"The allegations from Human Rights Watch say that Al-Shabaab recruits young children at the age of 14, 15 and 17 as soldiers. In Islam, a person becomes adult at the age of 15 so he or she must do what all other adults have to do,'' said Abu Musab, the group's military spokesman.
''If the territories of the Muslims are attacked, it is incumbent on the women and children to take up arms to fight the enemies, so we don't care what Human Rights Watch says,'' Abu Musab said, speaking to Alfurqan radio, which supports the group.
Islamic scholars consider a boy becomes a man at 15, or even younger if signs of puberty appear before then.
Human Rights Watch said this week that children as young as 10 increasingly face horrific abuse in war-torn Somalia as Al-Shabaab targets them to replenish its diminishing ranks of fighters.
The Somali insurgent group's recruitment of child soldiers is not new, but the report said the scale of child abductions over the past two years is like nothing documented in the past.
Shocking patterns have also emerged of children serving as human shields on the battlefields, according to the Human Rights Watch report released Tuesday.
"We're beginning to see more and more instances where children are essentially being used as cannon fodder," Tirana Hassan of Human Rights Watch told CNN.
The head of the Somali national army, Gen. Abdulkadir Ali Diini, said Wednesday the government does its best not to recruit children as soldiers.
The government has discharged children who are mistakenly recruited, he told journalists in Mogadishu.
Human Rights Watch charged in its report that Al-Shabaab fighters abduct young girls and boys from their homes or schools, in some cases taking entire classes.
Children can be sent out to recruit other children, according to the organization. One survivor told Human Rights Watch a group of kids asked him to play football at a nearby field. When he arrived, he and others were gathered up and sent to training camps, the survivor told Human Rights Watch.
The camps are places where children live in fear, said Hassan, an emergencies researcher for the international human rights group.
"They see injured and dead fighters, many of them children, coming back from the battlefield," Hassan added.
Recruits are taught to use weapons and to throw hand grenades and are subjected to a myriad of abuses, including rape, assault and forced marriages, according to Hassan.
Dozens of recruits, mostly ages 14 to 17, are driven by truckloads to the front line, where they are told to jump out -- only to be mowed down by gunfire while Al-Shabaab fighters launch rockets from behind, according to Hassan.
A 15-year-old boy recruited by Al-Shabaab from his school in Mogadishu in 2010 told Human Rights Watch that "out of all my classmates -- about 100 boys -- only two of us escaped, the rest were killed."
"The children were cleaned off. The children all died and the bigger soldiers ran away," the youth told Human Rights Watch.
Human Rights Watch also criticized Somalia's transitional government for not ending its use of child soldiers.
"Al-Shabaab's horrific abuses do not excuse Somalia's Transitional Federal Government," said Zama Coursen-Neff, the group's deputy children's rights director. "The TFG should live up to its commitments to stop recruiting and using children as soldiers, and punish those who do."
The 104-page report, released two days ahead of a Somalia conference hosted by the British government, grimly details countless violations against children based on more than 160 interviews conducted over two years with Somali youngsters who escaped from Al-Shabaab forces as well as parents and teachers who fled to Kenya.
"For children of Somalia, nowhere is safe," Coursen-Neff said.
On Thursday, senior representatives from more than 40 governments will converge on London in a diplomatic push to find political solutions to restore stability in Somalia.
CNN's Jonathan Wald contributed to this report.