Aid delivery to Haiti's quake victims is being slowed by damaged infrastructure, aid workers say, as UN chief Ban Ki-moon arrives.

The delivery of aid to victims of Haiti's earthquake is still being slowed by bottlenecks, aid workers say.

UN and Oxfam staff are finally bringing food and water to some parts of the capital Port-au-Prince, but the airport remains clogged with loaded planes.

Many survivors of Tuesday's quake have become desperate as they wait for aid, and many are trying to leave the city.

UN Secretary General Ban Ki-moon, who has arrived in Haiti, said it was the worst humanitarian crisis for decades.

Mr Ban visited the ruins of the UN mission, where several staff including Special Representative Hedi Annabi were killed, and meet President Rene Preval

.