Aid groups ramped up operations Monday for millions of drought-stricken people in the Horn of Africa, with the World Food Programme and the Red Cross expanding emergency food deliveries in Somalia. The International Committee of the Red Cross (ICRC) distributed food to 162,000 people in Somalia's insurgent-ruled southern regions, while the UN food agency increased its relief airlifts that kicked off last week. Since Wednesday, the WFP has delivered more than 80 tonnes of emergency food aid to malnourished children in Mogadishu and expanded the distribution to Doolow region in the south of Somalia. "Another aircraft arrived today, the sixth flight since the airlift began last Wednesday -- the airlift is an ongoing operation and will continue," said WFP spokesman David Orr in the war-torn Somali capital. "That brings the total amount delivered into Mogadishu to over 80 tonnes of specialised highly nutritious food for malnourished children." About 12 million people are affected by the devastating drought across the Horn of Africa, the worst to hit the region in decades. The United Nations has declared a famine in two regions of southern Somalia but the effects have been felt more widely across the country, as well as in parts of Djibouti, Ethiopia, Kenya and Uganda. The ICRC, one of the few aid groups allowed by the Al Qaeda-affiliated Shebab rebels to operate in southern Somalia regions under the rebels' control, said it had delivered 3,000 tonnes of food. "This is the first large-scale food distribution in that part of the country since the beginning of the year," the agency said in a statement. "But this distribution assists only a small percentage of those in need. More aid will be required to help the population bridge the gap until the next harvest in December," said Andrea Heath, ICRC's economic and security coordinator for Somalia. Malnutrition rates in Somalia are the highest in the world, and the relentless conflict and the drought have left millions in need of emergency humanitarian aid. Somalia has been the worst affected country in the Horn of Africa by the drought that has forced thousands of people to flee to neighbouring Ethiopia and Kenya. In the world's largest refugee camp in eastern Kenya, the UN children's agency UNICEF launched a mass vaccination against polio and measles. "Teams are going from tent to tent, to make sure all children aged between six months and five years are given life-saving vaccines," said Melissa Corkum, a UNICEF spokeswoman. "There are cases of measles in the camp as children are coming from Somalia, where immunisation is very low." Aid workers say they fear outbreaks of diseases in the overcrowded Dadaab camps, which currently host some 380,000 people and where some 1,300 Somalis arrive every day, according to UN estimates. "We are very worried about an outbreak -- we have people up to 29 years old with measles," said Antonia Kamore from the International Rescue Committee. "They are very weak on arrival, while mothers have had to leave some children along the way, so there is psychological trauma as well." Conditions are grim in the camps. "Life is so hard here," said Hawo Hassan Ali, who arrived in Dadaab three weeks ago after fleeing Somalia with her seven-month-old daughter, Suabo Osman. "We are getting some medical help, but the food is not enough," Ali added, as her daughter was vaccinated against polio and measles. In Ethiopia authorities are to open a new camp in Dolo Ado region near the Somali border that is planned to hold some 40,000 people. It will be the second camp to open since June, when the Kobe settlement was set up. Kobe is already full with 25,000 new arrivals and many more waiting for shelter at overcrowded transit centres.