The southern Sindh province is one of the worst hit areas to be flooded following monsoon rains in the country.
The latest floods have killed more than 230 people, destroyed or damaged 1.2 million houses and flooded 4.5 million acres (1.8 million hectares) in the past six weeks, according to officials and Western aid groups.
More than 300,000 people have been moved to shelters but an estimated 800,000 families hit by last year's floods remain homeless.
Pakistani military personnel distribute aid to flood-affected villagers in Jhudo district
Local authorities, the United Nations, and foreign and local aid groups are distributing water, medicine and food, while the army is rescuing people from communities trapped by the waters.
Victims of Pakistan's floods are at growing risk of potentially fatal diseases, aid groups have warned.
The director general of the Sindh Health Department, Hafeez Memon, said there were 2,000 confirmed cases of malaria and that number was likely to rise.
Pakistani leaders were widely criticised for neglecting victims of the 2010 floods that killed about 2,000 people and made 11 million homeless.