Aid groups say they are launching an emergency vaccination campaign for 140,000 people in Haiti to protect them against measles and other diseases.

The campaign is being conducted by the international Red Cross federation, the World Health Organization, UNICEF and the Haitian Health Ministry.

A Red Cross statement says the campaign will focus on the capital Port-au-Prince because the disease risk to earthquake victims there is greatest.

The federation said it expects to start by vaccinating about 1,800 people Monday at a camp on the old airport runway and then move on to hundreds of other camps over the next two weeks

Vaccinations will also be against diphtheria and tetanus.