Pakistani Prime Minister Yusuf Raza Gilani has directed the authorities to immediately activate the National Health Emergency Response Unit to urgently deal with the outbreak of water-borne diseases in the floods-hit areas in southern parts of the country as the death toll from flood-related incidents reached 123 in the country, said officials said Tuesday.

Most of the people died as a result of drowning in flood waters, falling roofs, snakebites and water-borne diseases including gastroenteritis, said health officials and aid agencies.

Floods triggered by heavy monsoon rains in southern Sindh province have so far destroyed nearly 500,000 mud houses, said Zafar Qadir, Chairman of the National Disaster Management Authority (NDMA

The NDMA chief informed the Prime Minister in a briefing in Islamabad on Monday that about 80 percent of standing crops have been swept away by floods only in Sindh province. He said that floods have so far affected 400,000 acres of agriculture land while 100,000 cattle-heads are dead or missing, according to a statement issued by the Prime Minister's office.

According to NDMA, 80 percent of bananas, dates, chili, sugarcane and cotton crops has been destroyed. This could cause a shortage of fruit and vegetable this year in Sindh and other parts of the country.

On Monday heaviest spell of rain also occurred in many parts of southern Sindh province. The meteorological office has forecast more rains this week.

Prime Minister Gilani took serious notice of the spreading of water-borne diseases in the flood-hit areas of Sindh and directed the relevant authorities to extend full support to the Sindh government for prevention as well as cure of these diseases, said the PM office.

The Prime Minister directed the NDMA chairman to start immediate aerial spray in the affected areas to stop the further spreading of these diseases.

The NDMA chairman apprised the Prime Minister that one hundred hand spray pumps are being provided for their utilization in the flood-affected areas to prevent the water-borne diseases.

According to NDMA's estimate, some 2.2 million people have been affected since heavy rains started in the first week of August and 300,000 displaced by the floods only in Sindh province. Thousands more have been affected in eastern Punjab province.

Many affected people have complained about shortage of food, clean drinking water, medicines and tents.

As the monsoon spell continues to inundate more areas, NDMA said that flood water may take up to two to three months to dry up. Officials fear an outbreak of water-borne diseases due to polluted domestic water supplies and standing water.

The World Health Organization (WHO) has warned in a report of possible outbreak of endemic disease in the wake of recent floods in southern Sindh.

Prepared in view of the survey of relief camps and flood-hit areas in the affected districts, the report said that skin diseases are fast spreading among the displaced people of the affected areas.

Acute shortage of clean drinking water, safe sanitation, shelter and healthcare facilities are likely to trigger serious health diseases, particularly among women and children, said the WHO report.

WHO has urged the government authorities to administer vaccination to the children, so that they are protected from falling victim to disease, particularly in the areas where there are inadequate safe drinking water and sanitation facilities and proper drainage arrangements.

Officials said that hundreds of people with diarrhea and other related problems have attended public health facilities over the past few weeks.

Health authorities have started a health awareness campaign across the province using the electronic and print media to encourage the use of boiled water for drinking and cooking purposes.