With monsoon rains expected to continue pummeling Pakistan for several more weeks, the United Nations on Friday warned that the south part of the Asian country could also be affected by deadly flooding, which has already affected millions of people.

Martin Mogwanja, the UN humanitarian coordinator for Pakistan, told reporters in New York via telephone that the devastation wrought by the current flooding is on par with that caused by the earthquake that struck the country in 2005.

He said that the floods — the worst in Pakistan in living memory — have affected 4 million people so far, with at least 1.5 million people having lost their homes.

The number of flood victims would likely increase in coming days, he said.

Mogwanja said that 1,400 people have been killed so far, “but this number may rise as new bodies may be found.”

The monsoon season could last up to four more weeks, with the possibility that the flooding — currently concentrated in northern Pakistan — could move south towards the Indian Ocean, affecting millions more people, he said.

Already, the central areas of Sindh province in the south have felt the effects of flooding.

The search-and-rescue and evacuation phase has come to an end, with many people having been moved to safer areas by helicopters and boats.

UN agencies have been rushing relief to the area since the early days of the disaster. The World Food Program (WFP) has provided 500 metric tons of food, while the UN Children’s Fund ( UNICEF) has distributed enough clean drinking water for 700,000 people. The UN High Commissioner for Refugees (UNHCR) has supplied 11,000 tents and the UN World Health Organization (WHO) has distributed dozens of cholera kits for health centers.

“However, this is only a small fraction of the response required given the scale of this disaster and also its geographic scope,” Mogwanja said.

In the hard-hit province of Khyber Pakhtunkhwa (KPK), formerly known as the North-West Frontier Province, it is estimated that between 30 and 40 percent of those in need of assistance have received help, but there are still many who have not been reached with aid.

“This is of great concern to us, which is why we are acting as quickly as we can,” the UN coordinator said.

Earlier this week, UN Secretary-General Ban Ki-moon announced that up to 10 million U.S. dollars will be disbursed from the Central Emergency Response Fund (CERF), set up in 2006 to allow the UN to dispatch funds to tackle disasters and crises as soon as they emerge, to help address needs in Pakistan following the floods.