At least 51 people were killed, 21 injured and 258,930 others affected by heavy rains and resulting flash floods in parts of Pakistan over the last 12 days, officials from the National Disaster Management Authority (NDMA) said Monday.

Reema Zuberi, spokesperson of the NDMA, told Xinhua that the torrential rains that have been lashing the country since July 15, swept away 1,648 houses, inundated 451 villages and destroyed standing crops on 233,688 acres of land.

Chitral district of the country's northwest Khyber Pakhtunkwa province was the worst-hit area where the gushing waters have killed at least 26 people and destroyed 350 houses.

Forty bridges and four roads linking the district to other parts of the province were thoroughly damaged, creating hindrance in the rescue and relief operation.

The flood water destroyed 11 irrigation channels and over 60 water supply schemes, cutting off the drinking water supply to the district.

A total of 13 people were killed, eight others injured and about 100 houses destroyed when heavy rains wrecked havoc in Pakistan administered Kashmir, the NDMA said.

At least seven people were killed, eight injured and 106 houses destroyed when the heavy downpour hit the country's south Balochistan province, the authority added.

In the country's east Punjab province, three people were killed, four others injured, 467 houses damaged, 356 villages affected, and 242,384 people became homeless and 233,688 acres of standing crops destroyed.

Up to 95 villages were inundated and 16,54 people were affected in the country's south Sindh province.

In north Gilgit Baltistan area, the heavy rains killed two people, injured one and damaged 625 houses.

Teams from NDMA, provincial governments and Pakistani army are carrying out rescue and relief operations in the affected areas.

The army has provided 249 tents, 724.52 tons of ration, 12 tons of drinking water to the flood affectees and also evacuated 40,727 people from the rain-hit areas.

Meanwhile, 180 people stranded in the flood water were shifted by an Army helicopter from Chitral to safe places.

The NDMA has provided 300 shelters, 24 tons of ration, one ton of drinking water and 20 rescue boats in the flood-hit areas.

Prime Minister Nawaz Sharif has announced a 5 million U.S. dollar aid package for Chitral, and visited flood relief camps in Punjab province on Friday, local media reported.

Monsoon rains hit Pakistan every year in June and the season normally ends in the first week of September. During this period, the country receives heavy rains which cause flooding in various areas.

The most destructive flood hit the country in 2010 in which parts of Khyber Pakhtunkhwa, Punjab and Sindh were affected. The flood swept away 20 percent of the land, killed 1,540 people and injured 2,088.

According to UN report, 557,226 houses had been destroyed, and over 6 million people had been displaced in the flood.