More than a 100,000 people have fled their homes after Saudi-led coalition air strikes began in Yemen, according to UNICEF.
A spokesman from the UN agency, Rajat Madhok, told Al Jazeera that most of those who have been displaced are women and children.
"Most displacements have taken place from and within al-Dhale, Abyan, Amran, Saada, Hajja. The displaced persons are mostly being hosted with relatives," Madhok said.
In a statement published on Tuesday, UNICEF, the UN agency that provides humanitarian assistance to children and mothers, said 74 children caught up in fighting had been killed and another 44 maimed since March 26.
"These are conservative figures and UNICEF believes that the total number of children killed is much higher," the statement read.
The agency's Yemen representative, Julien Harneis, said children were paying an "intolerable" price, and said more needed to be done to protect them.
"These children should be immediately afforded special respect and protection by all parties to the conflict, in line with international humanitarian law,” Harneis said.
The comments came as Houthi rebels and forces backing President Abd-Rabbu Mansour Hadi engaged in fierce clashes in the country's south, reportedly leaving more than 140 people dead in 24 hours on Monday.
Mohammed al-Bukhaiti, spokesperson for the Houthis, told Al Jazeera that the number of civilian casualties was not yet clear.
"We don't have a clear account of the number of civilians being killed but obviously the number is increasing due to the strikes and also the humanitarian situation is deteriorating due to the siege and strikes hitting food storages," he said.
Aden is a power base for Hadi, who fled to Saudi Arabia as the fighters from the Zaydi Shia sect expanded their control across the country.
As thousands are in dire need of aid, the International Committee for the Red Cross (ICRC) said that one passenger plane carrying staff was able to land in the capital Sanaa on Monday, but that the organisation has not yet been able to find a cargo plane operator to fly supplies into the country.
Sitara Jabeen, the ICRC's spokesperson, told Al Jazeera that the humanitarian situation was worsening.
"The situation in Yemen remains extremely critical. The conflict ... has intensified, especially in Aden. We are still trying to find a cargo plane that can carry our supplies to Sanaa," said Jabeen, speaking from Sanaa.
The Saudi-led coalition has bombed Houthi positions since March 26 and has dropped weapons to Hadi loyalists, but the rebels continue to put up resistance and have said they will accept peace talks only if the aerial attacks stop.
The Houthis swept into Sanaa in September and put Hadi under house arrest before he fled to Aden and then to Saudi Arabia. Backed by militias loyal to former president Ali Abdullah Saleh, they control large swaths of Yemen, which is also grappling with al-Qaeda.
Source: Al Jazeera and agencies