The World Health Organization says increased fighting in Somalia's capital has pushed the number of child casualties to a new high.

The group says children under the age of 5 suffered nearly half of the weapons-related injuries in Mogadishu last month. That number is up from 3 percent in April.

The WHO says the main causes of children's deaths were burns, chest injuries and internal bleeding from explosions, shrapnel and bullets.

The African Union and Somali government forces have mounted an offensive in recent months against the Islamist militant group al-Shabab. The group wants to overthrow the United Nations-backed government and set up an Islamic state. Before the offensive al-Shabab controlled all but a small part of Mogadishu.

In response to the child casualties, the WHO says it has trained 50 doctors and nurses in Mogadishu's Banadir Hospital on how to treat chest injuries and burns.

The U.N. says its humanitarian agencies and other partners have asked for $59 million to fund health services in Somalia, but have received only about $9 million.