At the United Nations on Tuesday, the Annual Report of the Secretary-General on Children and Armed Conflict was released showing record numbers of children recruited, used and killed in 23 conflict situations around the world.

"We have documented the cases of children recruited and used by seven national armies and 50 armed groups fighting wars in the Central African Republic, South Sudan, Syria, and in 11 other countries," said Leila Zerrougui, U.N. Special Representative on Children and Armed Conflict.

The 50-page report catalogues incidents from January to December 2013, showing the number of children used and killed in conflicts has spiked. There were 4,000 documented cases in 2013, but observers know thousands of other children are estimated to have been recruited and used.

In country after country, the report shows how many nameless children are killed in conflicts, used as suicide bombers or suffer from sexual violence. A typical excerpt from Afghanistan reads:

The majority of the children (72) were reportedly recruited and used by armed opposition groups, including the Taliban and the Haqqani Network. Nine of the children were recruited to conduct suicide attacks. In one incident, in May 2013, a 15-year-old boy conducted a suicide attack against an Afghan Local Police commander in Muqur district, Gazhni Province, killing three local police officers and two civilians, and injuring 16 civilians. Children were also recruited to manufacture and plant improvised explosive devices, as combatants and for other roles, including as sex slaves.

On the Democratic Republic of Congo:

The United Nations documented 910 children (783 boys and 127 girls), who had been newly recruited and used by armed groups. Among them, 609 were Congolese, 28 Rwandan, and 5 Ugandan, while the nationality of 268 children remained undetermined. Almost half of the children were reportedly used as combatants, but children were also used as porters, cooks, informants and in other support roles. Most of the girls were subjected to sexual slavery.

And Iraq, before the current crisis:

2013 was marked by a significant increase in the number of security incidents, resulting in the killing of 7,818 civilians, including at least 248 children. This is the highest number of casualties reported since 2008. The most affected governorates were Baghdad, Kirkuk, Ninewa, Diyala, Anbar, Wassit and Salahaddin. The Islamic State of Iraq (ISI) and Al-Qaida in Iraq (AQ-I) were allegedly responsible for most of the documented incidents.

The Nigerian terrorist group Boko Haram is included as a new party on the list of the Secretary-General for killing and maiming, as well as attacks against schools and hospitals.

"Boko Haram continues to commit unspeakable violence against children and I am deeply concerned by the fate of the numerous girls abducted in the past few months," said Leila Zerrougui. "The listing is part of the broader response of the United Nations and the international community to tackle the violence by the group."

Leila Zerrougui says, however, there is also progress in the report. "No violations were recorded in Chad in 2013 and the country's National Army has fulfilled all the requirements of its action plan. They are no longer on the list for recruitment and use of children."

The U.N. launched a campaign in March 2014 titled "Children, Not Soldiers." The ultimate goal is to ensure that no child is associated with parties to conflict -- ever -- anywhere by 2016.