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 U.N. 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 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 Shiite rebels and their allies began. 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. Gamila Hibatullah in Aden was quoted as saying. "Hospitals are overflowing, and even ambulances have been hijacked."

The International Committee of the Red Cross (ICRC) aims to fly two planes carrying 48 tons of medical help and other aid to Yemen over the next two days. Delivery of the aid shipments has been repeatedly held up as the ICRC negotiated clearance with the Saudi-led coalition which has mounted air strikes on Yemen's Houthi fighters for nearly two weeks. It also struggled to find aircraft to fly into Yemen. ICRC spokeswoman Marie Claire Feghali said it planned to fly the first plane, which is loading up in Jordan with 16 tons of medical aid, to Yemen on Wednesday. The second, carrying medical aid and other equipment including tents and generators, is being prepared in Geneva and will fly to Yemen on Thursday, she said.

Pitched fighting intensified on Monday in Yemen's second-largest city, Aden, leaving streets littered with bodies, as Shiite rebels and their allies waged their strongest push yet to seize control of the main bastion of supporters of their rival, the country's embattled president. The fierce fighting in the southern port city on the Arabian Sea raises doubts over the possibility of landing ground forces from a Saudi-led coalition backing President Abed Rabbo Mansour Hadi to try to carve out an enclave to which Hadi, who fled the country two weeks ago, could return. Saudi Arabia has asked Pakistan to contribute soldiers to the military campaign, as well as air and naval assets, Pakistan's defense minister said Monday. Pakistan's parliament is debating the request and is expected to vote in coming days. Houthi fighters and pro-Saleh forces attacked Aden's Moalla neighborhood, one of the last districts held by Hadi loyalists where the presidential palace, port facilities, TV, government offices and a military camp are located. The districts are on a peninsula that juts into the sea, meaning Hadi's forces are bottled up in the neighborhoods. "We are jumping over dead bodies," Radwan Allawi, a pro-Hadi fighter, told The Associated Press from Aden. He said mosque loudspeakers were calling on Hadi's supporters to defend Moalla. "It's intense street fighting, direct fire. The only difference between life and death may be an electricity pole behind which one can hide," the 20-year-old said. Pro-Hadi fighters destroyed three tanks deployed in Moalla by their opponents overnight, only to find new ones Monday. At least one residential building was in flames from the fighting. Coalition forces started an airdrop of weapons to Hadi's forces on Friday, but some military officials say the weapons are falling into the wrong hands. The number of casualties was not immediately known, with medical facilities in the city overwhelmed and volunteers coming under fire from rival groups.

Yemen's slide toward civil war has made the country a crucial front in mostly Sunni Saudi Arabia's rivalry with Shiite Iran, which Riyadh accuses of stirring up sectarian strife through its support for the Houthis. Sunni Arab monarchies around Yemen have condemned the Shiite Houthi takeover as a coup and have proposed a military intervention in favor of Hadi in recent days. The advance of the Iranian-allied Shiite Houthi group raises fears of the possible disintegration of the country. Sanaa has been under Houthi rebel control since September last year. The country has been facing severe political instability after the takeover of the presidential palace by Houthi militants prompted Hadi to tender his resignation. Hadi fled to the southern port city of Aden where he has re-established his presidency. As the country continues to be dragged into civil war, the U.N. has started to hold mediated peace talks between Houthis and Hadi's government in a bid to bring peace and stability back to the country.