Islamabad , Pakistan ( CNN ) -- Some 14 million people have been affected by the torrential rains and flooding that have left more than 1,000 dead in Pakistan , a spokesman for the national disaster authority told CNN Tuesday . While 1,245 people have been confirmed killed , officials believe the number of dead may reach 1,500 , said spokesman Ahmed Kamal . He said 1,334 people have been injured and 337,282 people have been rescued . More than 302,000 houses have been damaged , Kamal said , but that number might more than double by the time the flooding subsides . Most of the displaced have sought shelter in public buildings , including schools , said a spokeswoman for the United Nations High Commissioner for Refugees . They include thousands of Afghan refugees `` who have suddenly lost their homes for the second time . '' Pakistan 's Meteorological Department said more heavy rains were in store in the next few days , threatening to deepen the worst natural disaster the nation has experienced in recent history . The monsoon season is only halfway over . The flooding , which started in the northwest , threatened places as far south as the port city of Karachi . Nineteen people died across the country between Sunday and Monday nights , Kamal said . The weather in the northwest province of Khyber Pakhtunkhwa did improve slightly Tuesday , which allowed 23 helicopters to take off for relief and rescue operations , according to a military spokesperson who did not want to be identified . Kamal said 76 helicopters and 621 boats were participating in rescue efforts . Of those affected by the flooding , 6 million to 7 million are in immediate need of food and other items , said Maurizio Giuliano , information officer for the United Nations Office for the Coordination of Humanitarian Affairs . `` While not all may be in need of immediate humanitarian assistance , and the severity of their needs has not yet been fully assessed , this is a higher figure than those who were affected by the 2005 South Asia tsunami ( 3 million ) , the 2005 South Asia earthquake ( 3 million ) , or the 2010 Haiti earthquake ( 3 million ) , '' he said Monday in a statement . Though the number of fatalities was not comparable with either the tsunami or the earthquake , both of which had death tolls that exceeded 200,000 , Pakistan 's flooding `` is a major disaster of enormous magnitude , '' said John Holmes , U.N. Under-Secretary-General for Humanitarian Affairs and emergency relief coordinator . Many Pakistanis are not happy with the government 's response to the floods , saying it has been slow and ineffective . Pakistani President Asif Ali Zardari returned home Monday from an overseas trip , facing growing criticism of his actions following the massive flooding . He had been in England for talks with British Prime Minister David Cameron during the worst of the crisis . Prime Minister Yousaf Raza Gilani said a true assessment of the loss of life and infrastructure can be determined only after the water recedes . He appealed to the international community and to Pakistanis living abroad to help . Aid agencies scrambled to help those in need . `` The assistance that we have so far provided has alleviated suffering , but relief operations need to be massively scaled up , '' said Martin Mogwanja , the U.N. humanitarian coordinator in Pakistan . U.S. emergency relief teams continued to arrive in Peshawar to help , the U.S. State Department said . The U.S. Agency for International Development has committed $ 55 million in aid to international organizations and nongovernmental organizations , it said . The United States has provided more than 435,000 meals . This assistance is in addition to U.S. military efforts , which include rescue airlifts , food supplies and other deliveries provided by the Pentagon . Of the total , $ 20 million will be used to expand humanitarian operations farther south as the flood zone expands , Mark Ward , acting director of the Office of Foreign Disaster Assistance , told reporters Tuesday . CNN 's Reza Sayah and Samson Desta and journalist Nasir Habib contributed to this report .
NEW : The displaced in Pakistan include thousands of Afghan refugees . Recommend0 The death toll stands at 1,245 , Pakistani authorities say . 1,334 people have been injured ; 302,000 homes damaged .