Amman: More than 100,000 people in Yemen have left their homes in search of safety and at least 74 children have been killed since fighting in the country intensified almost two weeks ago, the UN children’s agency said.

Unicef said the violence has disrupted water supplies in areas of Southern Yemen and that sewage is overflowing in some locations, raising the risk of disease outbreak.

Hospitals are struggling to treat large numbers of wounded with insufficient supplies and some medical facilities have come under attack, the agency. It said at least three health workers, including an ambulance driver, have been killed in attacks.

Children are especially vulnerable, said the agency’s Yemen representative, Julien Harneis.

“They are being killed, maimed and forced to flee their homes, their health threatened and their education interrupted,” Harneis said in a statement, released on Monday in Amman, Jordan.

The agency said at least 74 children have been killed and 44 wounded since March 26, when a Saudi-led air campaign against Yemen’s Al Houthi rebels and their allies began.

The fighting pits allies of the country’s embattled president, Abd Rabbo Mansour Hadi, against the rebels and their allies, military units loyal to Hadi’s predecessor, ousted autocrat Ali Abdullah Saleh.

A Saudi-led coalition, which supports Hadi, has been carrying out air strikes targeting Al Houthis and their allies to halt their advance on Aden, Yemen’s second-largest city.

On Monday, fighting intensified in Aden, with the rebels and their allies making their strongest push yet to seize control of the port city, which has been the main bastion of support for Hadi. The clashes were so intense, many bodies were left in the streets.

The fighting raised doubts over the possibility of landing ground forces from the Saudi-led coalition to carve out an enclave to which Hadi, who fled the country two weeks ago, could return.

“Conditions are very dangerous right now,” Unicef’s Dr Jameela Hibatullah in Aden was quoted as saying. “Hospitals are overflowing, and even ambulances have been hijacked.”

Water systems have been repeatedly damaged in three southern systems, including Aden, the agency said, adding that it is providing fuel for pumping water. It said that in other southern areas, there are reports of water accumulating in the streets and sewage overflowing.

The agency estimated that more than 100,000 people have left their homes in search of safer areas.